Okeydoke folks I think I have picked my challenger.

Her name is Parsk the Undying and she is an (overgrown) water beetle larva. For some reason, she never pupated when she was supposed to. Instead, the shell of the beetle adult grew over her larval form, rendering her impervious to harm, but also cursing her forevermore with the larva's incessant hunger for flesh. If she doesn't eat enough, she'll get extreme hunger pangs and eventually wither up and die. But as she eats, she grows, and as she grows, she needs more meat to sustain herself. Seeing as meat is limited in her home village (at the bottom of a swamp, where cannibalism among beetle larvae is a normal part of adolescence due to limited animal matter), Parsk decided to move out to spare her kinsfolk and seek a more sustainable source of nutrition... by joining the Water Army.
Sketches:



Stats:
Beetle Carapace (all over body): Notoriously tough adult water beetle skin. Actually, because of this stuff coating her entire body, Parsk can no longer breathe/sleep underwater and must come up for air in aquatic environments.
Hollow Pincers (on head): Crushes enemy exoskeleton/armor, then pumps them full of digestive enzymes, then sucks the stuff back up. This is Parsk's primary method of feeding; her face/mouthpieces are mostly for communication, although she does occasionally eat things through her mouth (mostly human foods, like porridge, or anything served in a bowl).
Hollow Jet (in mouth): Shoots digestive enzymes.

Steam Spirelets (on back of abdomen): Vents scorching hot steam, heated by biochemical reactions. Parsk likes to stock up on extra water before battle, but in a pinch can boil her own hemolymph for an attack. She usually uses these spirelets to breathe.
Poison Tip (on tail): Bacteria-infested. Dangerous.
Her overall body plan is set. I am most unsure about the mouthpiece area and would appreciate feedback on that/how the current setup is looking, if it looks better with a second set of pincers on the mouth or not etc. I would also appreciate feedback on spirelet placement.
Sometime I will post an inspiration/moodboard for Parsk and also talk a little about the ideas I scrapped.