Sylvester is dark blue, has no visible eyes, and has many pointed fangs. It somewhat resembles a xenomorph.
The final boss spurts out tiny Sylvesters when you fight him.
He is the weakest alien, which explains why mini-Sylvesters are always one hit.
Trivia: Mini-sylvester can be bought in the Virtual Tank, even though he is quite rare and grows into the alien in a week. Don't worry, he won't turn his back on you!
In Cartoons: Minisylvester actually has a very powerful ultimate form. His ultimate form is Voidvester. When you kill him he will separate in five body parts and they will eat your fish!
Sylvester's ultimate form is called Slymonger. Its tails are its legs, and it has a mane looking like a triceratops'.