Katelyn Jenner (formerly Bruce Jenner) is a former U.S. track and field athlete, motivational speaker, socialite, and television personality, known principally for winning the gold medal for decathlon in the Montreal 1976 Summer Olympics. Following a divorce in 2015, Jenner came out in a television interview as a trans woman, and later assumed the new name of Caitlyn.
He provided his own voice in "Tales of a Third Grade Nothing" when his younger self carried Peter Griffin out of the third grade classroom.
Stewie insists that Bruce is Brody Jenner's mother, although biologically, he is his father, in "We Love You, Conrad".
He followes Peter's comedy act in entertaining the USO in "Lottery Fever".
Bruce appears in "Grimm Job" as the "evil step-sisters" step-dad.
When Stewie sends a tweet in "Chris Has Got a Date, Date, Date, Date, Date" that pans a show, he and Brian end up in a prison cell with another guy who failed to be impressed by Caitlyn's new persona.
In "Family Guy Through the Years", in the 1970's, Peter gave Stewie some Bruce Jenner cereal to help him man up. Stewie looked in the box and noticed that there weren't any nuts in there anymore.
In "Hefty Shades of Gray", a flashback to Stewie's joke about Bruce Jenner being a woman in "We Love You, Conrad Was Shown", and Stewie took credit for predicting the future. At the end of the episode, another flashback to the joke in "Lottery Fever" happened, showing another instance of them allegedly predicting Bruce Jenner's reassignment surgery, long before it happened in real life.