I got in!
And since nobody can post, it's the perfect time to post my Nabbit headcanons.
Nabbit is actually a Zelda character, as he's Ravio's brother and Nabooru's and the Happy Mask Salesman's child.
(He's not the Gerudo King born once a 100 years. Although he is a male and Gerudo off-spring, only the Gerudo King born once a 100 yrs has the classic Gerudo look, with the tan and red hair and all.)
Ravio took after his father and became a morally ambigious salesman, whereas Nabbit became a thief like his mother.
The Running Man is his uncle.
During the Imprisoning War, Nabooru was looking for a powerful husband to reign supreme over the rebelling Gerudos.
She sensed a powerful entity in the Happy Mask Salesman, who had indeed dimension-travelling capabilities.
They fled to Lorule since Termina was destroyed by the Moon.
The Running Man used his dimension-powers to spend his life dressed up as a plant on Isle Delfino.
This is quite a divine prank.
You see, after getting the Bunny Hood, he could hear the godesses.
As a joke, they said to the Running Man to flee and dress up like a purple plant.
Nabbit got lost in his dimension-warping and is now trying to get in Smash in order to warp back to his actual universe.
That's why he steals, he wants to show Mario his moveset potential.
Eventually he did but he died before he could get to see his brother Ravio.
Filled with regret, he became the Monster Merchant Kilton.
And since there's no lore that says this can't be the truth it obviously is.