I'm pretty sure that they are based on fanart character by dark dragon deception here it is

Other user who know, saying bithell and team made based on their art and dark dragon deception said "what?!" they did send it and d.d.d. was surprised that

The fact about havoc bonnie

Fans questioned the lack of a Havoc Bonnie character in > Dormitabis as he was the only main four animatronic that did not have a Havoc variant. It was explained by Blackout in many of his posts that the concept of a Havoc Bonnie never came to fruition and was an immediately discarded as it would not make sense in the game lore-wise. Blackout stated in a Q&A that if Havoc Bonnie was in > Dormitabis, "it would've been a fucked up version of the Bonnie Lamp from Fazbear's Fright" It is entirely possible that the Havoc Bonnie eventually evolved into Soulcage, as Soulcage has the same Bonnie Lamp as the main torso