Jacksepticeye is a YouTuber famous for his "let's play" videos, in which he plays a video game while delivering live commentary. He has made 'let's play' videos for all five of the Henry Stickmin games, just like his co-YouTuber Markiplier.
As a tribute to his Henry Stickmin videos, he has been given a cameo appearance in Fleeing the Complex. He appears during the Convict Allies route when Henry and Ellie release all the prisoners. He is seen running in the weapon selection area. You need to be quick to see him.
Red herring Edit
Later in the same route, another character with green hair is seen standing next to a hole in the fence. This character is often mistakingly believed to be Jacksepticeye as well. In fact, in his 'let's play' video for Fleeing the Complex, even Jacksepticeye himself thinks this character is his stick figure-counterpart, evidently having failed to notice the actual stickmin-Jacksepticeye in the earlier scene.