The Super Mario enemy named Tolstar did not originate from fanon, and more information can be found on their respective wiki(s). You may read more about him on the following wiki(s):


Tolstar is a greedy trickster originally found in the game Mario & Luigi: Superstar Saga. He is the ruler of the Stardust Fields, the border region between the Beanbean and Mushroom Kingdoms.

Tolstar's name probably derives from Tolstar forcing people (such as Mario and Luigi) to pay a toll to get across the border in Stardust Fields. It could also be either a play on the Russian word толстый (tólstyj), meaning "fat", or a portmanteau of the Russian author Tolstoy and the word star.


New Super Mario Bros.: The Search Of Fate

Tolstar is greedy and fat but also the ruler of Stardust Fields. He can suck you up and spit you out damaging you and downing you.