Planetary Absorption – The ability to absorb the energy and/or matter of an entire planet.
Galactus (Marvel) absorbs the life energy of planets for sustenance. Planets that cannot sustain life cannot provide Galactus with the life energy he needs. Galactus can absorb the energy of planets directly but uses also uses technology for planetary absorption since this is more efficient. Uatu the Watcher explains how this planetary absorption technology works in Fantastic Four V1 #49.
Starbreaker (DC) can absorb the energy of negative emotions, planets and/or suns. In Justice League of America V1 #96, Green Lantern explains how Starbreaker absorbs planetary energy.
The Awesome Eater (Savage Dragon) devours planets.