The animatronic roster of Ultimate Custom Night changed quite a bit during development, with the major changes including:

• Changing number of animatronics to 50 from 40.
• Removing Adventure Endo-01 and Candy Cadet as playable characters.
• Adding Withered Chica, Withered Bonnie, Phantom Mangle, Phantom Freddy, Phantom Balloon Boy, Nightmare Bonnie, Nightmare, Nightmarionne, Nightmare Balloon Boy, Old Man Consequences, Funtime Foxy, Helpy, Nedd Bear, Orville Elephant, and Molten Freddy all as playable characters
• Merging Nightmare Freddy and Freddles into one slot
• Merging Bucket Bob, No. 1 Crate, and Mr. Can-Do into one slot and renaming them to "Trash and the Gang"