Micro Rubber Engines are a range of engines that are modelled out of rubber. The wheels do not move and the engines are hollow. They are only available in My Busy Books.
- Toby and Mavis are incorrectly depicted as 0-4-0s and Spencer is depicted as a 4-4-2.
- Rosie, Emily and Whiff are somewhat oversized compared to the other engines.
- Annie and Clarabel's underframes are grey, when they should be black.