Why It's So Special: Essentially a one-joke character, this crazy angelfish spends his life hoarding the bubbles coming out of a ‘treasure chest’ in a dentist’s aquarium.
Yet in scenes involving Willem Dafoe, Allison Janney and Brad Garrett, Bubbles had to hold his own – so Andrew Stanton turned to veteran scene-stealer Root, cast on the strength of the similarly anally obsessed Milton from cult comedy Office Space.
Root speaks: "You can improvise. Any line from the film, you can do five minutes on it. Whatever catches their fancy is fine. It might be the first take. It might be the 25th. You're not memorizing; you're just coming in and playing. I love playing."