There are numerous Transformers fans out there who are not satisfied with the toys sold by Hasbro and Takara. They want more, so they build their own. These are the Custom Transformers. They range from simple modifications, where some paint is added or changed, to new figures built from scratch (or parts of other Transformers). Here you can see some of these.

Customs by Limewire Animated Silverbolt Armada Tidal Wave Botcon Huffer Classics Dirge Generations Bumblebee Movie Gridlock Movie Protoform Blackout Movie Protoform Bumblebee Movie Protoform Ironhide Movie Prowl ROTF Springer

Customs by Philister Animated Roadbuster Prime Tailgate

Customs by CakedUp Human in Disguise Maverick