Bo Gregory is a fish who attends Freshwater High. He owns tractors and trucks and has his own corn field.
Bo Gregory is friendly and kind, although he is not that bright. He is fond of having a simple life on his farm.
Bo Gregory first made an appearance when he went on a date with Bea. Later, when Oscar made up a fake girlfriend, Bo Gregory let Bea borrow his truck so they could reunite Oscar with Doris Flores Gorgeous ("Doris Flores Gorgeous"). He was crowned king of the school dance once ("Queen Bea"). When Oscar was looking for a new roommate, Bo Gregory came and hoped he did not mind if he milked his cow, Bessy, making Oscar disgusted ("Dances with Wolf Fish"). When Milo trapped everyone in bowls with his ninja, Bo Gregory got put in one because Milo thought that he could fall down while he is talking and hurt someone with his teeth ("Milo Gets a Ninja").
When Milo became a giant and smashed through the classroom wall, Bo Gregory was impressed and told the students he made a shortcut to Mr. Baldwin's room, calling him "stronger than a baby duck" ("Big Fish"). When Milo curled up into a ball and got thrown by Coach Salmons, he was tossed to Bo Gregory and told him to hit him. After Bo Gregory hit Milo, he told Coach Salmons the ball talked to him again ("The Dark Side Of The Fish"). Bo Gregory once allowed Oscar to ride in his car but his pet chicken in the back seat kept pecking Oscar's eye ("Riding in Cars with Fish").
When Bea and Milo tried to help Oscar pick out a club, they first suggested the milking club, which was led by Bo Gregory. They decided not to choose the club after they saw Dan and Ann Chovie milk a cow ("We've Got Fish Spirit"). When Bea lied to Chief after she won the audition for the Hokey Poke commercial, she, Milo, and Oscar saw Bo Gregory, who was riding a tamed scorpion. Bo Gregory advised Bea on how to ride a scorpion, which caused her to gain confidence, although the scorpion became vicious and beserk once Bea rode on it, making her fall and injure herself repeatedly ("Bea's Commercial").
He had a somewhat major role in "Cattlefish, Ho!", when Milo wanted to be a cowboy. Milo thought he was already one, but when he could not lasso a cow and told Bo Gregory he was supposed to tell him he was a good cowboy, Bo Gregory said "a cowboy without a cow is just a boy." Milo got upset, and later, when Milo accidentally burnt the dinner Oscar was making for the group, he told Bo Gregory he did not deserve the "dirt soup." Bo Gregory then served Oscar some dirt soup and told he was gonna stand there and stare at him until he eat it. When the cows caused a stampede after running away from Wilford, who was tapping at the glass, Milo started crying a lot, and the cows started drinking his tears. Bo Gregory told Milo to continue crying so that the cows would follow him back into the tanks.
- The logo on Bo Gregory's shirt is very similar to the Moods of Norway logo.