Yin-Yang — INANIMATE INSANITY

Yin-Yang holds unique abilities, like:

Stout strength: Yin-Yang is strong enough to kick both OJ and Paintbrush off of a cliff, and to kick Silver high up in the air.
Mindful positioning: They are able to have one of the halves take full control of the body.
Large Appetite: Yang was able to eat a whole uncooked pizza in one bite in Cooking for the Grater Good, and Yin was able to eat Dough in one bite in "A Kick in the Right Direction".

In Inanimate Insanity Invitational, Yang has become less chaotic, although he still retains his disagreeable traits. It also appears Yin is more annoyed by Yang and doesn't really try to fight him that much anymore. Yin-Yang has calmed down since Inanimate Insanity 2 but they still disagree a lot. As of "Out of Body Experience", after switching bodies with each other prior to the bridge incident, Yang promised to treat Yin better after realizing how he struggles. Later in the episode, despite losing the challenge, they realized that they reached a personal goal, which they agree counts the most. In "Pesty Besties", Yin even says he's glad Yang is with him to balance his unassertive-ness out.

Yin, the white half, is good-hearted, kind, honorable, and rational, whose intent is to balance out Yang, the black half, who is massively chaotic, malicious, loud and impulsive. While Yin is happy to participate in challenges and actively tries to help out, Yang despises participation and typically enjoys the misfortune of other characters, and will lash out and attempt to harm others, including Yin.

This difference in character makes Yin-Yang participation and handiness quite limited, sparking many enemies with others. Because they are attached, Yang does not get away with bad doings, for Yin can easily stop him.

When separated by Test Tube's experiment, Experiment 626, the balance between Yin and Yang got broken, causing Yang to become too chaotic, shambolic, destructive, and vicious on his own by breaking things and attacking characters. Though Yin was initially happy with the separation, he realized that his compassion was useless in this state and concluded that fusing back together into Yin-Yang is the only way to stop Yang's violence and balance him out.

In Inanimate Comics, Yin and Yang are shown to be able to get along with each other better than in Season 2, thanks to Cherries providing lessons, as well as finding a common interest in bug catching (Yin likes to be at one with nature, while Yang likes to be in control of it.)

Yin-Yang appears as a spherical form of the yin-yang symbol (symbol of taoism), split white and black by a wavy division, nearly in the Old Yin position. They have two arms and two legs, which both halves can control at their own will. Yin, the white half, is on the lower left-hand side, and Yang, the black half, is on the upper right-hand side. Sometimes, Yin is on the right-hand side, and Yang is on the left-hand side. Yin-Yang’s mouth is on Yin's side, with one eye shown black, whereas the other on Yang's side is shown white. As seen in "Try Not To Laugh Challenge," when Yang takes full control of the body, Yin's eye becomes white with a black outline. As for Yin taking full control of the body, Yang's eye becomes black with a white outline.

When separate, as shown in "Tri Your Best," Yin is a white sphere and Yang is a black sphere (Though Yin is the dark side and Yang is the light side).

In Inanimate Comics, Yin-Yang body rotates about 90 degrees clockwise from his design in the show almost in the Yin-Yang position.

In the last episode of Invitational, Yang had sharp teeth.