Siestar is a character exclusive to Sonic the Comic Online and the Ristar series. The star is supposedly the best "friend" of Ristar, yet will go to any length to achieve fame and popularity. To this end, he films Ristar singing in the kitchen while making pie and plans to show the video to the world, ruining Ristar's reputation. Siestar succeeds in publishing the tape, despite Ristar's efforts, yet the plan backfires when the public loves the singing and delight in their hero's hidden talents.
Siestar appears to be rather well-built and rather easily holds off Ristar's attacks. He aspires to be a rock star and sees this as another battle in the war of "pop versus rock". In the end, Siestar admits Ristar can't be forgotten about that easily.