Gravityrant

Gravityrant is the evolved form of Gravattack.

Appearance
After evolving from Gravattack, Gravityrant no longer has legs, and floats entirely by manipulating his gravitational field. His skin crust becomes more jagged, as crests and peaks form on the surface. His planetary core is engulfed in his mouth now, with a red spiral circling outwards. His hands are much larger then Gravattack's.

The most notable change, however, are the three smaller orbiting planetoids that spawn around him, caught in his gravitational field. They each have a little face on them that resembles Gravattack's original form in orbit mode.

Powers and Abilities
Like his devolved form, Gravityrant can control gravity to manipulate weight of objects, motion of objects, or slam them down to the ground with ease. Gravityrant can make matter or energy orbit around him.

Gravityrant can also manipulate his own gravity in order to levitate.

Like himself, his three smaller orbiting planetoids also have gravikinesis ability.

Being made of rock, plus his naturally large size, Gravityrant has enhanced strength and durability.

The long, pointy mountain peaks on his head and arms could easily be used as a sharp weapon.

Weaknesses
If  Gravityrant takes large amounts of damage to their core, it could meltdown and explode, much like an actual planet.

His large size makes fitting in smaller spaces difficult.

Smaller aliens (like Nanomech or the Hulex) would not be injured by his peaks.

Because he has no legs, he must use gravity on himself to make levitation, in order to be mobile at all.

Omniverse

 * Gravityrant(AKA Ultimate Gravattack) made his debut in For a Few Brains More. He was used by Albedo where he fought Ben by making him spin in his gravity to recover Azmuth's brain.

Ben 10: Omniverse

 * For a Few Brains More (first appearance; used by Albedo)

Trivia

 * Gravityrant somewhat resembles Geodude and his three smaller orbiting planetoids resemble Koffing from Pokemon.
 * Gravityrant also resembles Magolor Soul from Kirby.
 * Gravattack is the only Omniverse alien to make his debut in Ben 10 Omniverse and have an ultimate evolution.