Cannibal Planets

Synopsis
The Cannibal Planets were living planets that could extend huge grasping tentacles from what appeared to be craters, with which they caught their food. They could eat nearly any kind of matter with mouths that extended nearly one full hemishphere wide. There were at least 10 of these planets in the Alpha Centauri system, before they were shattered by Earth men in 2189.

It is likely that the planets were capable of moving through space, as they seemed to have infested the Alpha Centauri system. The inhabitants of the 16 surviving native planets had been forced to turn their own planets invisible, so they would not be eaten by the Cannibal Planets.