What is jeff from

[The Rizzler]

Because I know he isn't from subway

[Kitt 🌟 Stargazer]

He was created with a bunch of other shark dogs and I believe Glen Stacey ends up finding him and keeping him as a pet. He's also been owned by a few other characters like Dead Pool.

[DoremianCleff]

Also he is a decently popular character in one of the Marvel mobile games. He is a mascot character. And frankly, Marvel need to push him harder. He has a widespread appeal, even if he won't have deep lore of other characters.

[Kyo Tanaka]

He's from Westcoast Avengers where MODOK in an attempt to instigate ♥♥♥♥, created invading land sharks. After the battle with MODOK was over, they were all back at base, with Gwenpool carrying a baby land shark asking if they could keep him.

Then Jeff has his own online comic shorts line in the name of "It's Jeff!"

Then later on, during a period where comics were being canceled left and right for obvious reasons (DEI nonsense causing an all time low interest in comic books), Gwenpool gives Jeff to Deadpool because of all the Marvel Comic characters, he's the least likely to get canceled. Jeff's continued existence would be safe with him. She knows it's only a matter of time before her comic line gets canceled too, and Jeff would be dragged down with her if she keeps him.

Yes, Gwenpool can see the fourth wall, in fact she's from "the real world."