The Alien Planet Portal is one of the two portals in Hungry Shark Evolution. The portal is found near a crashed spaceship (deep within the area where the Tiger Shark starts). If the Tiger Shark or bigger sharks are not used, the portal seems to be inactive. Moving near it causes the screen to zoom out, and it can teleport you to the Alien Planet.
Caution in approaching the portal is mostly advised, since an Enemy Mr. Snappy often spawns, guarding the portal.