These little guys swim around in aquatic areas and do almost exactly the same thing as the water mites, but instead of fleeing from a predator, they reveal their gigantic spikes of death until it goes away. If a creature tries to eat one while its spikes are out, it will receive some pain, wounded, and punishment instead of the usual stimulus. They are classed as beasts, so that you won't come back to a pile of stardust, because the creatures' first instinct was to eat these if you do an aquatic/carnivorous Wolfling Run with them around.
The Spiky Mites are supersized like normal. The gigantic death spikes deter most fish, so there isn't a reason to make it physically possible for a fishy to eat one. These are also Sabertooth-compatible, but they won't provide much sustenance, alive or dead, because most of their bodies are composed of hollow spaces the spikes retract into and bug guts that taste horrible. The dead bugs don't give pain and wounded, but they still give punishment because of bad taste.
Hitting these is pretty much killing them and ripping their spikes out and creatures receive pain and wounded from that, because ripping spikes out of something they're firmly attached to hurts.