Uncle Leo is the uncle of Bea, brother of Mrs. Goldfishberg, Mr. Goldfishberg's brother in law, the husband of Aunt Cassie, the father of Chester, Todd and Vicki, and the owner of the family Siberian Husky fish, Otto. He is voiced by Neil Patrick Harris.
He and his family are invited to the family reunion and bringing in cookies all the way from Fish Florida. Leo can be friendly around Oscar, Milo and Bea's relatives.
He is extremely laid back, mild mannered, mature, friendly, and very skilled as a farmer at they're house.
He looks just like his sister, but with indigo fins, flippers, Orange and Yellow Hawaiian trunks, light green swimsuit, and red flip flops with sun with sunglasses.
- Leo is obsessed with chocolate and raspberries.
- Leo and his family lives in the farmhouse and the farm, with cows, pigs, goats, sheep, chickens, ducks, bunnies, and Vicki's white horse, Lizzie.
- Unlike his family relatives, he is from Fish Florida rather than Fish Idaho.
- He works as a farmer.
- He speaks in the surfer dude accent.
- He dislikes potatoes, blueberries and zucchini.
- Leo rents an RV with a mini screen TVs, on the driver's seat,the flat screen TV on the back, Aqua marine carpet, red rug, and 3 beds in Todd, Chester and Vicki's room, and the king sized bed for Leo and Cassie to sleep in.