Diseased Scaylions are large Scaylions with general appearance very similar to that of Scaylion Workers but almost twice larger, have more health, and are much more of a threat. They are distiguished by three-pronged tails and green clouds which can sometimes be seen in their wake. They launch gobs of corrosive goo when at medim range or they spray their targets with stream of corrosive liquid when close. This attack is easy to avoid as Diseased Scaylions tend to stay in place and spray the liquid in a fairly limited horizontal arc.

Diseased Scaylions are only partially immune to corrosive but very vulnerable to incendiary and explosive damage.