Space Gate

From the Super Mario Wiki
A Space Gate in Super Paper Mario

Space Gates are doorways in Chapter 4-3 of Super Paper Mario. There are two Space Gates in the chapter, with the last and only eventful one located in the Outer Limits which leads to the Whoa Zone, an unusual world that was once the location of the Squirpia kingdom. The two Space Gates (before they are revealed) have one and two holes for Squirps to get in, respectively. For the first gate, if Squirps gets in the hole, the actual gate will automatically be revealed. For the second gate, Squirps must go into one of the two holes and have the player feed him a Sweet Choco-bar, a Shroom Choco-Bar, or a Golden Choco-bar (which can be bought from the Twinkle Mart found in the same level) so he splits into two and goes into each hole, revealing the actual gate.