Knuckles the Echidna was first seen to visit the Ice Cap Zone (gaining access through a Zoom Tube) when something crashed there from space. He discovered it to be Doctor Robotnik in his Death Egg, who tricked Knuckles into believing Sonic the Hedgehog was after the echidna's Chaos Emeralds. Knuckles later returned after Robotnik's betrayal, keen to destroy the Penguinators and Star Pointers still remaining there. Sonic the Hedgehog joined him and the two tracked down Robotnik in his Eggloo, disposing of Inter-Zone Technology that was sending Badniks down to the Hill Top Zone.