Family Guy has seen hundreds of characters come and go in its zany twenty-one year tenure. The majority of these, some from as far back as the 1999 pilot, have made multiple appearances in some form or other since their debut in the series. But, like most long-running sitcoms, there are always a few memorable faces that slip through the net.
Some of these characters fulfilled their roles adequately, leaving a lasting impression while not outstaying their welcome. Others seemed to have massive potential that we only got a meagre glimpse of. Regardless, both cases represent those who crossed paths with the Griffin family only once, yet have somehow lingered on in viewers' memories right up to the present day.
Of course, even the most minor of Family Guy characters can crop back up now and then around the town of Quahog, so true one-timers on the show are rarer than you might think. For this reason, non-speaking cameos such as in the Season 18 episode, Coma Guy, aren't eligible for this list - only major appearances that have an active impact on the storyline.
With this in mind, here are some of the best characters from Family Guy who only feature in a single episode.