In the early 2010s, when live speedrunning marathons were just beginning to find a wider audience and Super Nintendo games still dominated the front page of charity streams, a runner named “Carl Sagan” began turning a colorful platformer about Yoshi into one of the most technical showcases in the scene. Under the handle CarlSagan42, microbiologist Andy Diamos built a reputation first as a world record holder and marathon runner for Super Mario World 2: Yoshi’s Island, then as one of the defining creators and interpreters of kaizo and troll levels in Super Mario Maker.
Over more than a decade, his work has tied together tool-assisted speedruns, world record chases, marathon commentary, and a deep interest in teaching players how games actually function. His legacy sits at the intersection of high-level execution, accessible education, and a very specific kind of mischief that Mario Maker fans now simply call “troll levels.”
Yoshi’s Island And The Making Of A Speedrunner
Carl’s first widespread recognition came through Yoshi’s Island, a game that would become his signature speedrun. Community records and fan wikis preserve him as one of the early leaders of the category. In February 2012 he set a world record in the any percent warpless category with a time of 1 hour 49 minutes 16 seconds, a benchmark that stood for about a year before it was surpassed in 2013.
The run was not just about clean movement. Yoshi’s Island is built around egg throwing, enemy manipulation, and delicate control of the baby-timer mechanic, and early world record routes demanded that runners master all of it while navigating hardware quirks and random elements. On community forums he documented the progression of his times and the push to reclaim his record when a Japanese runner briefly overtook him, describing how a new 1:48:07 personal best required both new tricks and unusually favorable luck on key bosses.
From the start, Carl’s presence in the scene mixed technical mastery with explanation. Viewers who watched his early streams or VODs did not only see record attempts. They heard a runner who broke down how boss fights worked, why certain routes were faster, and which glitches were safe to use in a real-time run. That approach foreshadowed much of what he would do later in Mario Maker.
Yoshi’s Island At Games Done Quick
Games Done Quick marathons turned Carl’s lab-honed patience and his Yoshi’s Island expertise into a recurring spectacle. At Awesome Games Done Quick 2013, he ran Yoshi’s Island 100 percent in a live setting, with viewers donating to choose between any percent and the longer full-completion route. The event preview described the choice in vivid terms, promising either a sprint to beat his own world record in any percent or a 100 percent showcase where he challenged Japanese times with elaborate “eggy pyrotechnic” tricks.
AGDQ 2013 introduced many viewers to Yoshi’s Island as a true speedgame. The 100 percent run, clocking in around two hours and forty-plus minutes, showed a long sequence of stage-specific optimizations and crowd-pleasing glitches that were far removed from casual play. Marathon audiences were used to Super Mario World and other traditional platformers, but Yoshi’s Island’s flutter jumps, damage boosts, and boss quick-kills felt like a different branch of Mario altogether.
Carl’s relationship with GDQ did not end there. Over the following years he returned for multiple Yoshi’s Island appearances, including later marathons where he shared the couch with other runners such as mt76907 and rheal for multi-runner commentated showcases. These events cemented his reputation as one of the game’s key ambassadors.
TAS Collaboration And Technical Experimentation
Behind the scenes, Carl was also deeply involved with tool-assisted speedruns. On TASVideos he joined Baxter and NxCy on a landmark Yoshi’s Island 100 percent TAS that completed the game in 1:59:35.12, published in early 2013. The project required thousands of inputs and a granular understanding of how every enemy, platform, and projectile behaved.
TAS forum threads from the period document the team steadily grinding through the game’s worlds, with Baxter noting that the three of them were “at 6-8” and still had the extra levels to complete after that. For viewers, the finished encode was a nearly flawless ballet of eggs, momentum tricks, and improbable survivals. For Carl and his collaborators, it was also a way of mapping the outer limits of what the game’s engine could do.
This mix of real-time records and TAS work helped shape Carl’s later teaching style. Having spent years squeezing frames out of Yoshi’s Island, he was used to explaining not only how to perform tricks but why they worked at the code or physics level.
Microbiologist, Scientist, And Streamer
Unlike many early speedrunners, Carl did not come from a background of full-time content creation. Community discussions and later write-ups identify him as a microbiologist who completed a PhD and worked on dengue virus vaccines, a role that requires a high degree of technical training and patience.
That scientific identity remains part of his public persona. His Twitch profile greets visitors with the line “I play mario games and I also love science~~,” and channel aggregators describe him as an American microbiologist, speedrunner, and streamer known for Mario games. He has appeared in interviews and long-form conversational streams where he talks about laboratory work, vaccine research, and the parallels between scientific problem-solving and deciphering a tricky platforming level.
For many viewers, that combination of “science brain” and playful experimentation is part of the appeal. When Carl explains a glitch, it often sounds like a miniature lecture on systems and emergent behavior, but it is delivered with the enthusiasm of someone who still enjoys seeing Yoshi break through a wall that was never meant to be passable.
From Yoshi’s Island To Kaizo And Mario Maker
By the mid-2010s, Carl had begun moving from traditional speedrunning into a new frontier: kaizo and troll levels in Super Mario Maker. The Wii U release of Mario Maker in 2015 allowed players to create levels that previously required ROM hacks, and Carl quickly became one of the most visible faces of this emerging scene.
Community wikis summarize his trajectory clearly. The Kaizo Mario Maker Wiki lists him as an American microbiologist and streamer best known for Yoshi’s Island and Mario Maker, noting that he later became widely recognized for popularizing troll levels. He uploaded dozens of Mario Maker levels, including the Kaizo College series intended to teach difficult techniques, and infamous creations like “Carl’s Premature Detonation,” which challenged players with precise bomb setups and punishing traps.
As a player, he gravitated toward the hardest community creations. Early Twitch VODs and YouTube playlists show him grinding through “hard levels” and blind kaizo stages, including notorious works by creators such as PangaeaPanga. One Destructoid article on the AGDQ 2016 Super Mario Maker hard level race quoted Carl’s on-air commentary, where he described Panga as one of the “very sadistic individuals” who used the game’s tools to create “horrifying levels for our amusement.” It was a joking line, but it captured the emerging ethos of kaizo and troll design: levels as puzzles, pranks, and skill tests all at once.
Kaizo College And The Language Of Difficulty
One of Carl’s most lasting contributions to Mario Maker is the concept of Kaizo College. Rather than simply create brutally hard stages, he used the game’s tools to design a curriculum of sorts, with levels that intentionally taught shell jumps, cape tricks, on-off switch timing, and other building blocks of high-level play.
Other streamers often showcased these stages. Series like “Kaizo College: Getting Schooled by Carl Sagan” and related playlists introduced console players to the idea that kaizo could be learned through structured practice instead of only suffering through full hacks. Players on community forums asked for recommended orders to tackle his Kaizo College levels, treating them as a ladder of difficulty rather than scattered one-off challenges.
The pedagogical impulse behind Kaizo College mirrored his earlier approach to Yoshi’s Island. Where many creators simply chased shock value, Carl built levels that tried to communicate. He used visual cues, repeated setups, and controlled difficulty spikes to give players a chance to internalize new techniques, even as they died repeatedly along the way.
Troll Levels, Juzcook, And Community Storytelling
As his Mario Maker career continued, Carl became more and more associated with “troll levels,” stages built around misdirection, fakeouts, and creative use of the game’s rules to surprise the player. His YouTube playlists include hundreds of videos devoted to such levels, often with titles that play up their cruel humor.
He did not only play troll levels. He helped shape the standards for them. His community maintained a Discord server where creators could submit troll stages, and levels that earned enough reactions typically became candidates for his streams. A Mario Maker 2 discussion thread on Reddit points players directly to that server as one of the best ways to find high-quality troll content.
Among the most famous stories to emerge from this era is the “troll war” with fellow creator Juzcook. According to the Kaizo Mario Maker Wiki, Carl’s level “Juzcooked Alive” helped kick off a back-and-forth series of troll stages that each tried to outdo the other in creativity and cruelty. For viewers, these exchanges were more than a series of isolated clears. They became a form of serialized storytelling, with each new level referencing previous gags and escalating the rivalry in unexpected ways.
Super Mario Maker At Games Done Quick
Carl’s history with Games Done Quick also carried over into Mario Maker. By AGDQ 2016 he appeared not only as a Yoshi’s Island runner but as a member of the Super Mario World 0 Exit race and a central figure in the marathon’s first Mario Maker segments. The AGDQ 2016 schedule lists him both on the SMW 0 Exit showcase and on the Yoshi’s Island couch that year.
Mario Maker’s flexibility made it especially well suited for marathons. Hard level races, blind relay races, and showcase blocks let runners demonstrate both individual skill and cooperative problem-solving. An SGDQ 2018 lineup article later highlighted the return of Mario Maker with multiple blind relay races and a hard level speedrun by Carl as a veteran runner, framing him as one of the anchors for the format.
His involvement continued into the sequel era. At AGDQ 2020 he joined other notable creators such as GrandPOOBear, Ryukahr, and others for Super Mario Maker 2 segments. In early 2024 he returned to the stage as the on-screen host of a Super Mario Maker 2 glitch showcase, then participated in a Reddit “Ask Me Anything” where he discussed the run, the game’s evolving tech, and a decade of GDQ appearances.
Through those events, he helped define how marathons could present kaizo and troll content to wider audiences without losing the in-jokes and technical depth that made those communities special.
Teaching Through Trolls
Taken together, Carl’s Mario Maker output looks less like a random sequence of levels and more like an extended teaching project. On Twitch, his streams often carry titles like “Happy Little Troll Levels,” a tongue-in-cheek nod to Bob Ross that also hints at his intent: to show that even the cruelest stages can be read and understood.
He spends long stretches dissecting setups, explaining why a particular spring or pipe works the way it does, and encouraging viewers to look for patterns rather than brute-force their way through. In that sense, his microbiology background and his speedrunning history converge. Troll levels become experiments, and each death a data point in figuring out what the level designer wants you to think and how they intend to subvert it.
This approach has made him one of the most recommended Mario Maker creators for new viewers. Lists of prominent Mario Maker streamers often single him out for his ability to tackle savage troll levels while staying analytical and composed, noting that his long history with ROM hacks and speedruns underpins his success.
Ongoing Streaming Career
Even as the speedrunning landscape has shifted to new games and platforms, Carl remains active as a creator. His Twitch channel still focuses heavily on Mario games, especially Super Mario Maker 2 and related kaizo content, and his YouTube channel hosts hundreds of edited runs, compilations, and highlight reels.
Channel statistics sites and Twitch tracking services place his follower count in the high hundreds of thousands, reflecting a sustained audience that has followed him from the Yoshi’s Island days through Mario Maker and into other titles such as Outer Wilds and indie platformers.
The tone of his streams has changed over time. As Mario Maker’s player base has matured, so have the in-jokes and level designs, but the core remains familiar. He still pauses to explain what is happening on screen, still reacts with a mix of laughter and exasperation when a troll gets him, and still returns to genuinely difficult platforming as a way to test his limits.
Legacy In Speedrunning And Kaizo Culture
Within the history of speedrunning and Mario platformers, CarlSagan42 occupies several overlapping roles. As a Yoshi’s Island runner, he helped elevate a complex, lesser-known Nintendo platformer into a marquee marathon game, setting multiple world records and collaborating on landmark TAS projects that mapped out the game’s possibilities.
As a Mario Maker creator and player, he helped codify the language of kaizo and troll design on modern consoles, showing that punishing levels could also be fair, readable, and even instructive. The Kaizo College series, his troll level showcases, and his long-running rivalry and collaboration with designers such as Juzcook all contributed to a shared culture that now reaches far beyond his own channel.
Finally, as a scientist turned full-time streamer, he has embodied a particular kind of “explainer” role within gaming culture, using the precision of laboratory work and the curiosity of research to make even the most arcane glitches and level tricks feel understandable. For viewers who discovered Yoshi’s Island or Mario Maker through his runs, Carl is a reminder that speedrunning is not only about raw reflexes. It is also about understanding systems deeply enough to play with them, teach them, and sometimes, in the case of a well-designed troll, weaponize them for a good laugh.