Since the movie, I finally got to see what Freddy looked like as a kid and needless to say that he was a cool kid. Bet he was a shy bean, too. This is Gabriel, Angel's crush who now possesses Freddy Fazbear.
Backstory: When he was alive, he wanted to become a famous music artist. His favorite animatronic was Freddy and he looked at him as an inspiration. Angel (being like Abbey) wanted to be a well-known artist and game developer (me irl too). And Angel knew that of Gabriel and wanted to surprise him by gifting him a Freddy plushie by using her few fazcoins she had at the time. But unfortunately she couldn't tell him "Hey I have a crush on you and I wanna be your girlfriend and support your dreams." Because he was lured by "the yellow rabbit" (-Ahem-) when he said to Gabriel "You wanna be a singer? Let's start now. Freddy will gladly give you some lessons." And ofc being a kid, he fell for the trap and before he knew it, boom....Killed. Now he fr possesses Freddy. Angel only found Gabriel's black bow that he had where he was killed. No evidence ofc but yanno, she only found his bow. And so she not only has Gabriel's bow but also the Freddy plushie she wanted to gift him.
Where is his bow now: When Spring Bonnie grabbed him, he grabbed the bow but thankfully Gabriel knew how it attached. So after getting rid of it, Spring Bonnie got pissed and threw it on the ground and finally killed him. So hints again the bow only being found cause it wasn't attached to Gabriel when he died. Only Angel retrieved his bow and still held onto both that and the Freddy plushie she wanted to give him.
How did he find Angel again: He found her through Abbey after finding out the truth of why she acted the way she did. And after he gave a care, he trusted Abbey enough to say "If you're Angel then I remember you. I'm Gabriel, the kid you liked. And he liked you, too." So, they're together even as robotic critters.