Garrett was initially successful as a stand-up comedian in the early 1980s.Taking advantage of that success in the late 1980s, Garrett began appearing in television and film, in minor and guest roles.
Garrett attended UCLA for less than two months before dropping out to pursue his comedy career.
Garrett has won three Primetime Emmy Awards, with three other nominations.
He is still prominent within stand-up comedy and is also a professional poker player.
He then appeared in the short-lived summer comedy First Impressions (CBS, 1988), in which he was a divorced father who makes a living doing impressions, in a one-time spot as a bank loan officer on Roseanne (ABC), and The Pursuit of Happiness (NBC, 1995–96), in which he was the hero's gay best friend.
Though prior to these roles, Garrett had also had a minor part on Transformers, voicing the Decepticon base Trypticon in season three and as an ill-fated thug in Suicide Kings.