He's a pygmy marmoset.

[ not a small stuffed pig best friends with a honey-obsessed bear, but jyn does eat honey out of the jar with a spoon so maybe he also is exactly that. ]

We went out past the wall when the EMP hit and I took him home. [ a beat. ] I thought he was dead, actually, but when I opened my bag he leapt out and tried to bite me.

[ and now he is her beloved pet. ]