Celeste.
She's a mischievous, magical being that loans a lot of money to Lane on many occasions throughout the story. And it being Lane, of course, he doesn't pay back a single cent. Ever. And whenever she catches him, she convinces him to pay the money back by ~other~ means.
Most of the wild and crazy stories involving Lane, including him being turned female, all the bits with slime, blueberry stuff, and various types of inflation, all involve Celeste.