Glow Fly

WARNING: When facing off with these creatures, it is vital to kill/disable them before they can move or have great mana pool/regeneration. With the exclusion of Evolution and Radiation immune units, this creatures passive will inflict a mana draining status effect, which when reaching 0 will start PERMANENTLY lower the targets max hp. Evolution can restore herself by transforming, otherwise there is no way of regaining the lost stats.

Aside from this nasty passive glowflys also have a similar mechanic to the mushroom boss. Instead of creating more allies, they create copies of themselves and all of them can use regenerate. If you can't out damage this encounter in the first 2-3 turns you'll, be swarmed by a full map semi immortal bugs. Large scale attacks like meteor storm or tsunami are advised. Furthermore, having your entire team be immune to radiation will slow down glowfly growth in numbers.

On the other hand, if you manage to capture one of these creatures, you can create a 1-2 turn full mana restore generator, by feeding it mana, or attacking a non radiation immune ally in a safe spot.