pip grows when you play with him
Pip now earns xp. Poking him, asking him things, hovering over notes and rolling the dice in the workshop all count, and he remembers in your browser.
He starts out as a head and two feet. Keep going and he gets arms, then legs, then a second antenna. There is a pencil sketch in the margin of the home page with the caption "legs?". I took it personally.
Only he knows when the next change comes.