Mini Spek

Mini Specs are cubic wind-up toys presumably sold by the Mario Toy Company. They first appeared in Mini Mario & Friends: amiibo Challenge. Mini Specs are spawned when the player uses a non-Mario series amiibo.

Mini Mario & Friends: amiibo Challenge
It is revealed from the first trailer that Mini Specs will debut in Mini Mario & Friends: amiibo Challenge. Unlike other playable minis in the game, they are not shown to have any kind of special ability, other than what regular minis were capable of in previous games in the Mario vs. Donkey Kong series.