Galilean

Galileans are bulky planetoid aliens from the planet Keplorr.

Physiology
Galileans are large, bulky aliens with rocky skin, a reddish-orange core on their chest, four reddish-brown fingers, and three grey toes.

Although Galileans are traditionally reddish-brown, they come in other colors such as magenta and violet.

Powers/Abilities
Galileans can manipulate the gravity of other beings and objects, making them either lighter than air or incredibly heavy. Their gravitational aura comes in different colors, including white, green, red, and mint green.

Galileans can retract their limbs and manipulate their own gravity, allowing themselves to assume a planetoid form and levitate.

Galileans can make objects revolve around them while in their planetoid form.

Due to being living planets, Galileans can survive in the vacuum of space.

Weaknesses
If a Galilean takes a large amount of damage to their core, they could meltdown and explode, much like an actual planet.

A Galilean's large size makes fitting in smaller spaces rather difficult.

Sudden changes of mass can throw Galileans off their orbit.

Omnitrix Transformation
The Omnitrix's Galilean representative is named Gravattack, who first appeared in the Omniverse episode "A Jolt From the Past". Gravattack solely appears in Omniverse.

The Ben Tennyson of Dimension 23 has an equivalent of Gravattack named Orbit Man, who was confirmed to exist in the Omniverse episode "It's a Mad, Mad, Mad Ben World: Part 2".

Gravattack has also been used by Albedo and Bad Ben.