Yumyulack Solar Opposites fans usually show up expecting the brains of the operation.
The little blue guy who calls himself a scientist is really the family’s weapons expert with a cruel streak and a surprisingly soft center. He is the replicant of Korvo, one of four aliens stranded on Earth, and he spends most of his time shrinking people who annoy him.
That gap between what he claims to be and what he really does is the whole joke.
Yumyulack wants to be taken seriously as a genius.
What we get instead is a self-proclaimed bounty hunter who lobotomizes a classmate over some light teasing.
Name: Yumyulack (family surname: Solar)
Species: Shlorpian replicant, from the planet Shlorp
Role: The team’s security and weapons guy, and a self-proclaimed scientist and bounty hunter
Pronouns: He/him (Shlorpians have no fixed sex)
Voiced by: Sean Giambrone
Known for: The Wall, the shrink ray, and torturing humans “to study the human condition”
Who Is Yumyulack in Solar Opposites?
Who is Yumyulack Solar Opposites really?
He is one of the four Shlorpians at the center of the show.
The crew crash-landed on Earth after an asteroid destroyed their home planet. Their real job is guarding the Pupa until it terraforms the planet. Their actual daily life is a lot messier.
The team splits neatly in two. Korvo and Yumyulack hate Earth and its people. Terry and Jesse love it here. That divide drives most of the family’s arguments, and Yumyulack sits firmly on the grumpy side.
For context, Solar Opposites was created by Justin Roiland and Mike McMahan and premiered in 2020. Roiland left the show in early 2023, and Dan Stevens took over as Korvo starting in season four. Sean Giambrone has voiced Yumyulack the whole way through.
The Wall: Yumyulack’s Creepiest Hobby
Here is the thing that makes Yumyulack unforgettable. He shrinks humans who irritate him and drops them into a giant terrarium built into his bedroom wall. The residents call it “the Wall.” He calls it research.
The people inside build a whole brutal society down there, and the show treats it like its own mini series-within-a-series.
He shrank Cherie for serving him shrimp he did not order. A guy named Tim got shrunk for wearing a red shirt. Yumyulack says he is studying the human condition.
The humans he traps would strongly disagree.
It should make him a monster. Somehow it makes him weirdly fascinating instead, because his cruelty comes from not understanding people rather than truly hating them.
Yumyulack and Jesse
His bond with Jesse is the beating heart of the character. She is Terry’s replicant, she is slightly older, and she is everything he is not. Jesse wants to fit in with humans. Yumyulack wants to shrink them.
They fight constantly, but the care underneath is real:
- In “The Unstable Grey Hole,” Jesse tries to show him humanity’s good side. He fires back by dragging her to a bar full of Neo-Nazis, then guts the whole room to save her when they attack.
- When Yumyulack was badly hurt, Jesse rushed him to the hospital and told him “thanks for not dying.”
- In “Retrace-Your-Step-Alizer,” he discovers Jesse built a nicer fake version of him named “Funyulack,” and he spends the episode trying to become less of a jerk to her.
That last one says it all. Under the shrink rays and the torture pods, Yumyulack wants his sister to like him.
What Yumyulack Looks Like
Yumyulack looks like a smaller, lighter version of Korvo, which tracks since he is Korvo’s replicant. The key details:
- Light-blue skin with bluish-gray speckles across his forehead
- A grayish-tan vest with white shoulder pads over a long-sleeved shirt
- A utility belt loaded with pockets and a silver buckle
Then there is the hair. He has a single tiny strand on top, and he is deadly serious about it. In the season one episode “The Lavatic Reactor,” faced with a head-shaving threat, he flat-out declares that his hair defines him. In season four the whole family gets human forms, and his comes with short, curly dark-tan hair.
Did you know? The family’s shared last name is “Solar,” which Terry basically made up for them. Yumyulack also has a strange obsession with Sigourney Weaver. He keeps a poster of her in his school locker and has even met her on the show.
Yumyulack’s Personality
Cunning, crabby, and sly is the short version. Those three words capture Yumyulack Solar Opposites in a nutshell. Yumyulack loves pranks, loves gadgets, and loves what he calls “sci-fi shit.” He claims his sharp instincts come from a past life as a bounty hunter on Shlorp, which he says explains how he handled that Neo-Nazi bar so easily.
His talent for over-the-top revenge is where the show goes darkest and funniest:
- He hijacked his school’s computers to run his own AI as a joke.
- He shrank and lobotomized his classmate Lydia after she teased him and Jesse.
- He keeps a rotating collection of shrunken people, “for science.”
After Korvo and Terry tell him to stop torturing classmates, he technically complies. Then he switches to experimenting on adults, insisting they “love it.” They very clearly do not.
Tyler’s take: The post title calls him the alien scientist, but I think that undersells the joke. Yumyulack is the kid who read one science textbook and decided he was a supergenius, then used that confidence to build torture devices. He is not the smart one. He is the dangerous one who wants to be the smart one, and that is far funnier.
Yumyulack and Korvo
Yumyulack and Korvo get along better than you would expect from two aliens this prickly. Yumyulack respects him, even if he shows it in a backhanded way. He once summed up his feelings by saying Korvo is “mean, but being mean is tight.” For a character this guarded, that counts as a love letter.
The Many Deaths of Yumyulack
For a main character, Yumyulack dies a lot. Death is almost a running gag in Yumyulack Solar Opposites.
Two moments stand out.
In “The Solar Opposites Almost Get An Xbox,” he accidentally kills Terry for a bit. A family brawl breaks out between him, Jesse, and Korvo.
It ends with Orgo, an ogre clone of Korvo, stomping Yumyulack and breaking his back. He gets resurrected by the end of the episode, first as a tree, then back to normal.
The second one is the clip below. In the Halloween special, Yumyulack trips on a fake cobweb, lands on a decorative fence spike, and dies. He then spends the whole episode in Hell, laughing off every torture the demons throw at him before getting hauled in front of Satan.
Yumyulack’s Family
His family tree is as strange as everything else about him:
- Korvo is his progenitor, which makes Yumyulack his replicant and “son.”
- Terry is the household’s other dad and the fun one.
- Jesse is his co-replicant and slightly older sister.
- Annie is an ex-girlfriend.
- Cindeen is his ex-wife.
- Yumyulack Jr. is his presumed son, who first shows up looking like a tiny purple beetroot.
Who Voices Yumyulack in Solar Opposites?
The voice of Yumyulack Solar Opposites belongs to Sean Giambrone, best known as Adam Goldberg on ABC’s The Goldbergs. He gives Yumyulack this perfect mix of teenage whine, dry menace, and buried vulnerability.
That combination is exactly why the character lands. A flatter read would make Yumyulack just a jerk. Giambrone makes him a jerk you cannot stop watching.
Is Yumyulack a favorite of yours?
Drop a comment and let me know.