Aristotle is a pink axolotl wearing a short purple cape held in place by a blue collar holding a purple gem in the middle. He was your father and Dutch's "ex" husband, as they were getting divorced because Aristotle cheated on him with Arthur. He was in Dutch's office with him, and they were talking about the divorce.

When Dutch mentioned organizing a wedding for him and Arthur, Aristotle wanted to reject him.

You don't have to do it, Dutch.