Yin-Yang

Yin-Yang is an amalgamation of two characters: Yin and Yang. The two halves have vastly different personalities that contradict each other. They share one body and are in constant disputes, even over simple tasks, such as what direction to walk or what to drink.

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.)

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.