|This character exists primarily or exclusively within the Sonic Underground continuity.|
Information in this article may not be canonical to the storyline of the games or any other Sonic continuity.
Doctor Robotnik used Luke Periwinkle in a plan to split up the Sonic Underground, threatening to roboticize him if he did not pretend to be the twin brother of Queen Aleena, and thus the uncle of the Sonic Underground triplets. Robotnik also put him in an iron mask (actually a surveillance camera) and locked him in a tower, where he was soon rescued by Sonic Underground.
In order to drive a wedge between the hedgehog siblings, Periwinkle claimed that Mobius could only have one ruler (as most real-world monarchies do; however there have been cases of coregency occurring historically in real life), and that he had been exiled and imprisoned when Queen Aleena took the throne. This led to the band arguing about which of them would eventually ascend into power (Sonic claiming that when he becomes king, he'll assign positions for his court to his siblings, for instance) and eventually calling it quits, after which Periwinkle helped Dingo capture the three of them. Only Sonic became suspicious of his story and nearly escaped, until Robotnik ordered Periwinkle to knock Sonic out himself.
However, once Robotnik has captured the hedgehog triplets and locked them up, he imprisoned Luke Periwinkle as well since he was no longer useful. Sonia finally recognized him as an actor and he explained the whole story. They were soon able to escape by means of the iron mask, which had been booby-trapped by Robotnik and they used to blow up the door. Periwinkle decided to give up acting and join the resistance.
- Luke Periwinkle's name is a reference to the actor Luke Perry.
- The word periwinkle refers to a type of sea snail as well as a shade of blue.
- Periwinkle's claim that he is Aleena's twin brother is a reference to "The Man in the Iron Mask" by Alexandre Dumas, in which the twin brother of Louis XIV of France is locked up and forced to wear an iron mask so that nobody can recognize him and he is not a threat to the throne.