Soymilk is the actor/stunt-horse/real life pet of Jodie O'Rodeo. She loves her, and she loves her back.

What good friends! But not much else is known about Soymilk, other than that she loves Jodie so much, she actually finds her after her and Lenny were trapped in the Novelty company's buildings.

Lenny from Fake Mustache

Lenny with Soymilk and the Sticky Hand, as depicted by concept art.