Sphoeroid

Spheroids are a species from the rainy planet Scalpasc. Spheroids are large, green, blowfish/lizard-like creatures with tan undersides. As their species name suggests they have round, fat bodies mostly dominated by their "head". They have stubby legs that end in stubby feet, similarly shaped like that of a rhinoceros' foot. Their arms are short and end in bloated 4-fingered hands, and they have a long lizard-like tail. Their face consists of a large, jaw-filled mouth with black lips, which are cornered by round, yellow eyes. They also have 3 green "quills" on their forehead, and 2 tan ones on their chin.

Abilities
Spheroids are able to expand to spew massive amounts of green, semi-adhesive slime. Also, their teeth suggest they can bite their foes.

Origins
In Ben 10  Secret of The Omnitrix". Spheroids are pirates of Scalpasc. Their job was to help silicon-based lifeforms by melting materials by getting from ocean worlds.  After, some quit their purpose.  Now they steal supplies, weapons, food and ships - even treasures.  They love the new way of living, like a true pirate.  Spheroids can escape from prisons like Encarcecon by using their teeth, slime and acidic spit to be free and head back home.  Spheroids' spaceships that look like a futuristic pirate ship, built for sea, air and space.

Behind the scenes

 * Their name is a play on the word "sphere".