Waterston lent his voice to the animated television series Family Guy where he played Dr. Kaplan, the psychiatrist Brian Griffin consults during his mid-life crisis in the episode "Brian in Love".
Waterston lagde stemme til den animerede tv-serie Family Guy, hvor han spillede tegnet Dr. Kaplan, som var psykiater for Brian Griffin som behandlede hans midtvejskrise i episoden Brian in Love.