Bert Banana is a recovering alcoholic/drug/sex addict who eventually found Jesus and cleaned up his act along with his fiance Tammy Tangerine and friend Mortimer Mango. He is voiced by David Cross, and appears is in the episode "Bible Fruit" where the trio meets Frylock online and visits his house. He is an annoying Christian proselytizer, bugging Frylock about his faith while regailing the Aqua Teens with stories of their former debauchery, including beating Tammy so hard he needed to have his hands surgically replaced, but claims "all that's behind us now", with the trio instead "hooked on G.O.D".
This is proven wrong less than a minute later when he notices Frylock's rum and promptly devolves into a ranting, booze-hungry maniac, threatening to beat Tammy again and demanding access to the U-trap in the kitchen so he can drink from the pipes after Mortimer pours the rum down the drain. After a failed prayer intervention from Tammy, the Aqua Teens flee the house in fear and he begins tearing the place to pieces in a fruitless search for any drugs he can get his hands on. Frylock ends up distracting the fruits by claiming Shake is full of crystal meth, then blowing the house to smithereens while outside on the lawn with Meatwad.
He also makes a brief cameo in the episode "A PE Christmas" with Tammy and Mortimer.