Alberto Guppy

Alberto Guppy is a PIE intern who turned out to be a genetic experiment created by his unknown parents.Johnny Ghost and Johnny Toast initially thought he was crazy for thinking he he was a fish.

Investigation of The Werewolf of Wyoming
Alberto first met Ghost when he was homeless and tried to live in a fish, Ghost took pity on him and gave him a gob as an intern.He was taken on the investigation of werewolf sightings in Wyoming where he met Toast for the first time.They kept trying to convince him he wasn't a fish but eventually gave up and just rolled with it.Alberto turned out to be integral to the investigation by finding the secret door they needed to go through to get further along.They eventually found the secret lab owned by Alberto's parents and it looked as if that is where the werewolf escaped from.It turned out that both Alberto and the werewolf turned out to actually be genetic experiments created by his parents, the werewolf actually being his sister.It is unknown how Alberto escaped the werewolf attack or how he lost his memory of being an experiment.

Johnny Ghost
Johnny took pity on Alberto when he found him homeless and gave him a job, he also tried to help convince him that he wasn't a fish.

Johnny Toast
Alberto and Toast don't know each other well but Toast seems find him annoying.

Parents
Alberto doesn't know who his parents are and just recently found out he was a genetic experiment created by them.

The Werewolf
He hasn't met the werewolf and doesn't remember how he escaped from her.He recently found out she was his sister as well as a genetic experiment that was also created by his parents.

Amelia
Alberto mentioned at one point that

when he thought he was fish he was owned by a girl named Amelia as a pet.It may be possible that she is his sister/the werewolf's human form.