The Menninkäinen is a one-time villain in the Disney XD series Milo Murphy's Law, only appearing in the episode "Star Struck".
In the episode, movie actor Tobias Trollhammer describes the Menninkäinen as a goblin from Scandinavian folklore that is said to steal souls; even riding a two-headed monster that has flaming eyes.
When Milo Murphy comes over to the film set, Trollhammer mistakes him for the Menninkäinen (due to Milo wearing a hat similar to the one that the Menninkäinen is wearing). Because of this, Trollhammer starts to panic and runs off, resulting a chase throughout all of Danville to bring Trollhammer back.
During the chase, Milo reminds his friends of the folklore and that he used to watch a television show featuring the Menninkäinen as one of the title characters.
Eventually, Trollhamer gave up running away after learning that Milo actually wanted an autograph when the latter saved him from falling over a bridge with a boat anchor.