The Symbiote: Mutualism; once the nanoprobes enter Josh's system, his body adapts to their presence and they become a biomodification. The fact that Josh's body doesn't remember how to work without them, coupled with how quickly they consume their energy source, is often a plot point. Taken further in season 3 where the primary power source is lost and it's implied that Josh will eventually die with only the smaller backup source trying to fill in for it.
Villain Ball: Dread misses more than one chance to kill Max because he wants him alive to study his biomodifications, and Max, every single time, escapes and ruins his plans.
Villainous Breakdown: A minor one in his last appearance, where he expresses shock at Max coming back from the most impossible situation he'd ever been in. It's not very spectacular, but it's a major display compared to Dread's usual calm, professional demeanor.
Disney Death: Psycho goes through a lot of these, to the point where both he and Max lampshade it. Taken to its absurd extreme when Psycho is thrown into space with no means of stopping his inertia or changing direction, to say nothing of re-entering the atmosphere without burning up and landing without going splat, but comes back a few episodes later.
The Dragon: To Dread at first. He begins acting on his own during the last season.
Genre Savvy: He ventured into this sometimes, though never quite enough to save him.
Villainous Breakdown: He is less than thrilled when he hatches a plot in season 3 that has nothing to do with N-Tek or Max like all of John Dread's schemes, but it turns out Max is there anyway by sheer coincidence.
Motive Decay: His original motivation was to carry on the eco-terrorist plans of Bio-Constrictor. By "The Toxic Legion" he's just interested in Morphososnote which, being Extroyer's power source, doesn't even have anything to do with Elementor
Extroyer (Troy Winter)
Animorphism: Can morph into animals by "Extroying" them.