Toadbert is a local resident of Toad Town, based on the character of the same name from "Mario & Luigi: Partners in Time". He idolizes Mario and Luigi after they help him with a plumbing emergency, and like Mario he dreams of being more than who he is. Toadbert has wanted to join the Toad Brigade ever since he was little because he thought it would help give him a purpose, he has a desire to help others, and he's never had anything to make him stand out from other Toads.

While Toadbert is canonically male, since the Toad voice doesn't have any distinct male or female qualities, gender is irrelevant when casting this part. I imagine him having something akin to the Toad voice, but more like a generic young boy mixed with the character Bentley from the "Sly Cooper" games.

*This role doesn't have many lines, but if I feel it would help add to the video, I can add additional dialogue.