I believe it's the source image of the shadow Bonnie fnaf 3 leak. It was on a 10 year old post on some old russian ask forum. It's higher quality, less stretch and lack the 3 in the corner.

Also on the Spanish wiki I found this buddy.

Apperently there's a rumour where if you beat 10/20 deathless you will get this fella. That's it really.