Imperceptible to the natural senses and usually incorporeal, this tiny paradimensional is attracted like a magnet to neural activity, probing into the brain with its prehensile "feeler" and steadily transferring information from the host brain to its own crude nervous system, emitting an almost audible twittering as it squirms in apparent ecstacy. What it gains from this process is not known, as its own minimal brain is almost incapable of active, conscious thought and has a memory span of mere minutes. If undisturbed, it may remain attached until the victim is little more than a vegetable.
An obliviote "solidifies" only in death, and melts soon thereafter. The implications of its striking physiological resemblance to a delphinid are not understood. Its similarities to the Lobotomask are unlikely a coincidence, as they have been found clinging tick-like to these larger psychovores, bloated to extreme proportions with no apparent harm to the host.
This is my way of adopting the original, defunct Thought Eater from Dungeons and Dragons into Mortasheen without cheaply copying it completely...which I didn't entirely succeed at, I suppose.
Does this go "too far" though? I mean, with what's blatantly a penis it uses to violate brains? I thought it might not be too controversial, because it's also just a mindless, tiny dolphin-fetus, draws from the underground reputation dolphins have as sick deviants and runs with the theme I've had of dolphin-based monsters being the most horrible and disgusting.
I have plenty more ideas for awful dolphins, too. I kind of want to have one in almost every class some day, except for Arthropoids because that wouldn't make sense with the rules I laid down for them.