You mean his half-brother Bertram, he first appears in Emission Impossible and returns in Sibling Rivalry, his final appearance (aside from him being the final boss in the Family Guy Video Game) is The Big Bang Theory.
He also makes a return appearance in the video game, Back to the Multiverse.
Brian Does Hollywood
Brian the Bachelor (Season 4)
Brian: Portrait of a Dog
Saving Private Brian
Play It Again, Brian
Brian the Bachelor
A Woody
Brian Does Hollywood
Brian the Bachelor
Brian is in every episode
Brian & Stewie's Emmy appearance & performance wasn't part of any Family Guy episode.
Brian the Bachelor (Season 4)
Brian: Portrait of a Dog
The episode is titled "Brian the Bachelor" and appears in season 4 (episode 7).
Meet the Quagmires is episode 18 of season 5 of Family Guy.
Saving Private Brian
Brian Writes A Bestseller Series 9 - Episode 6