Marvin the little purple tank steam worker

I don't know much about Marvin(since Adam didn't do Marvin's Wikipedia article, and can't view his information on Martine's gallery), but he is Thomas and Martha's son, he is purple, and he has the number 1 on his shoulder tanks(I don't know why he has that number, since his dad is already no. 1).
Marvin belongs to: browneyedsaiyangirl.deviantart…

In this, Martha is just annoyed as she is looking at Thomas' cocky look.