|“||Wait, wait. Allow me to explain. Granted, at first I desired only to bang out a quick cheap one with your universe, but it's your own fault. Your universe dresses provocatively.||”|
–Yivo in The Beast with a Billion Backs
Yivo is a sentient, extraterrestrial being from another universe, who communicated with universe "gamma" through the space-time hole called "the anomaly" made in Bender's Big Score. Shkle makes Fry the pope of a new Religion, whose adherents are encouraged to "love the tentacle". Yivo used shkler "gentacles" (as proclaimed by Leela) to have sex with every living being in the gamma universe except Leela, unbeknownst to them. Shkle is shown to be sometimes saying mean things to Humans.
In another universe, there existed only one sentient being, Yivo. For a trillion years, shkle was satisfied with shkler life as the lone being of that universe. But when shkle looked across immensity, shkle saw the Big Bang and said, "Whoa. Who's that?". Shkle realized that the newly formed universe was shkler soul mate, including every living being in it. Some centuries ago, shkle sent an image of shklimself into the artists of the gamma universe, portrayed as Heaven.
When a space-time rift opens between gamma universe and Yivo's (at the end of "Bender's Big Score" when Bender causes too many time paradoxes, causing the space-time anomaly to appear), Fry is the first to cross the barrier (as Robots couldn't) and meet Yivo. Yivo saves Fry from lack of oxygen and that sent shkler tentacles into the neighboring universe, sticking every living being but Leela with shkler tentacles and declares Fry the Pope of a new religion whose main tenet is to "love the tentacle". However, when Leela reveals that Yivo's tentacles are in fact "gentacles", Yivo admits that shkle was planning on mating with all of them, but shkle realized that everyone is shkler soul mate and releases everyone from shkler tentacles.
Yivo promises to make a clean slate, going out on a date with everyone in the gamma universe at the same time. However, though everyone had a great time, the leaders of the gamma universe feel that shkle can't make any form of commitment to them and decide to break up, only for Yivo to propose marriage. Shkle invites everyone onto shkler back where Heaven is and makes them promise not to contact other universes. Everyone enjoys their eternity with Yivo, except Leela, who is suspicious of the monster but eventually comes to accept shklim. Suddenly, the robots led by Bender attack Yivo, pulling shklim out into their universe, where they strangely are able to harm it. Yivo discovers that their weapons are lined with the paper Electro matter that Fry sent to Bender in the form of a letter. Heartbroken that Fry broke his promise, Yivo breaks up with the gamma universe, but allows Colleen O'Hallahan to stay, as she is the only one who shkle can connect with. As shkle begins to shklufocate, Yivo returns to Shklim's home universe with Colleen.
Yivo was an all knowing creature that yearned for love. When shkle discovered universe Gamma, shkle first was interested in simply having sex with the beings of that universe, which shkle later tried to justify because universe Gamma "dressed provocatively". Shkle soon changed after this incident and later began a monogamous relationship with Colleen after shkle found out that Fry broke his promise.
- Yivo is entirely composed of electro matter, which is impervious to all forms of assault in the gamma universe. The only thing that can cut through electro matter is more electro matter.
- Yivo is entirely covered in seemingly infinitely stretching and infinitely numbered tentacles, which when stuck in someone's neck, forces them to fall in love with the monster.
- Yivo seemingly has the ability to extend golden escalators, and spawn infinite number of tenctacles from other tentacles.
- After Bender attacked Heaven, Yivo is revealed to have a beak under shkler mouth of clouds. Possibly so Yivo would resemble the mythical kraken, leading to Yivo and Bender having a standoff parodying the climax from the 2006 movie Pirates of the Caribbean: Dead Man's Chest. Shkle also bears a resemblance to the Sarlacc from the 1983 movie Star Wars: Episode VI – Return of the Jedi.
- Yivo has the ability to revive certain lifeforms like Kif. Though it's unknown how shkle does this.
- Anyone living on Yivo becomes immortal, for e.g. Colleen.
- True to it being heaven, Yivo can grant the desires of anyone that inhabits shkler.
- Yivo is similar to H. P. Lovecraft's Outer Gods such as Azathoth and Yog-Sothoth.
- Yivo is based on God in the Bible but differentiates from him in a few humorous ways. Yivo is also based on Ego, the Living Planet from Marvel Comics.
- Yivo is a sexual predator who sexually assaulted the entire universe, after grooming it from a young age. Shklee also isolated them after starting a relationship, which also suggests further abusive behavior