Gastral's Light form is a squid-like alien with six tentacles and one eye. His skin is a translucent sky blue.
The Omnitrix symbol is located on a black strip connecting to his eye.
When in his Heavy form, Gastral's skin changes to orange and takes on a more humanoid appearance. His tentacles wrap around the chest and the black strip extends to accommodate the change in appearance.
The Omnitrix symbol is located on his chest.
- Internal Gas Manipulation- Gastral's body is made up of a gas that he can change the density of. The denser the gas the darker his skin gets. At his Heavy form, he gains strength and weight. At his Light form, he can fly and is lighter than air.
- Chemical Manipulation- Gastral can manipulate his body temperature, getting hot enough to evaporate water when coming into contact. He can also generate a cryo-based chemical to help him combat the heat chemicals.
- Jelly Physiology- Gastral can shape his body parts into weapons like hammers. His body can also be squished and stretched without any harm to him. This ability also allows him to regenerate.
- Water- Water can break down Gastral's body into sludge. While he can evaporate water, Gastral cannot evaporate the water if he's fully submerged.
- Dispersion- Gastral can be dispersed, but the regeneration process is slow.
- Fluiditois- The Fluiditois is Gastral's predator. It can spray an enzyme that is harmful to Gastral. It also has similar abilities to Gastral.
The planet of Gelrara mainly consists of almost earth-like mountains, with very little space for valleys, and light rays from the systems sun being a rare sight. All mountains are connected to each other as one large landmass, with very steep slopes. Hail storms of Carbon dioxide are common on the planet, but normally sublimate into gas almost instantly and typically goes from solid to gas after experiencing earth-like pressures. This makes it difficult to navigate for those not native to the planet.
Despite all of these traveling issues, most of the species on this planet don’t have too much issue traversing it. The dominant species of the planet being the Fluidozoa. Round jellyfish-like species, with one eye that also has the same properties as their bodies, multiple tendrils, and typically range in height from around twelve inches to five feet tall. They use gas pockets within their almost gelatin like bodies to fly around at high speeds and can change this gas into a more heavy and dense version, changing their forms to become much more gigantic. This allows them to solve tasks that would require heavy lifting, such as moving rocks and other heavy objects in order to find a narrow, hidden area to sleep or possibly lay eggs.
- Gastral was heavily based on Flubber.
- Fluidozoa is a combination of two words, Fluid, and Medusa from the Medusa Jellyfish.
- Gastral is a great choice for Mountain side rescues. His light form being used to carry away survivors and injured, and his heavy form for moving aside large rocks.
- Gastral's body has a feeling similar to a cold water balloon.
- Gastral's Heavy Form was based on Yellow Devil from Mega Man.