Similar to the homunculus of last post, the Imp is a potential familiar for Lawful Evil magic users, though there are so many caveats on rolling special familiars as opposed to birds, cats, toads, etc that they mostly seem like set dressing for NPC magic users. Though they could be very effective assassins with disguising polymorphs, a save or die stinger, invisibility, and flight, they are 90% likely to not fight for their masters.
Their presence does offer a variety of bonuses like a sensory link between the imp and it's master, 25% magic resistance if the imp is right there, +1 level, and 6 questions per week as per a commune spell. But if the imp dies, the 'master' loses 4 levels of experience, and any silver or magic weapon could do the trick, so all in all an Imp familiar may prove more of a liability against informed foes despite its usefulness as a resilient, sneaky monster and the magical advantages.
I think they would be more interesting if they would offer to enter a familiar pact with any willing wizard, with the goal of corrupting them to the service of hell. They also make for an interesting weakness of villainous wizards.
AD&D Intellect Devourer
As the lore of these creatures became more developed (as bodysnatching minions of mind flayers) they departed somewhat from their origin, which well deserves its description as "one of the most feared of monsters."
There appears to be either a flaw in my own understanding of AD&D Psionics, or in the description of Intellect Devourers, because, apart from the four dagger-like claws used to multiattack, these creatures do not appear to have any ability to attack non-psionic targets, for their attack modes of C and E correspond to Ego Whip and Psychic Crush, while the text mentions Ego Whip and Id Insinuation, but no psionic attack mode save for Psionic Blast actually functions vs non-psionics.
Ignoring this however, for a giant brain on legs (as the AD&D variant is medium sized, rather than brain sized, a possible typo given that they were even then meant to 'house themselves in the mindless body'.) they have an inexplicable form of invulnerability. They are immune to normal weapons and 'most spells' and +3 or higher magic weapons do only 1 point of damage- better even than the fabled demon lords. Fireballs only count as 'bright light' and lightning bolts deal only 1 damage per die. Death spells have only a 1/4 chance of success, and power word kill slays them. No explanation is given for this, alas.
Bright light and protection from evil drive them off or keep them at bay, which are some fairly accessible weaknesses that at least make up a little for their nigh-invulnerability.
All in all, the idea of brain-eating (and replacing) monsters seems good, but runs into a similar problem as the succubus, where there are implied potential situations of subterfuge and deception, which are then somewhat ruined by the lack of a true need to engage in those situations in that way, due to the complete lack of danger that situation poses to the would-be deceiver.
AD&D Invisible Stalker
A creature I think has a serious case of overlap with Aerial Servants, despite being significantly different. Both invisible, both servants summoned from the plane of air. Stalkers seem to be physical, intelligent, and stealthy, while an Aerial Servant is essentially an Air Elemental. Stalkers seek to subvert commands occasionally, while Servants just go berserk if thwarted. They are discussed almost entirely in terms of how they serve their masters, rather than what they 'are'. It is even mentioned that stalkers can be seen dimly on certain planes of existence, but not what they actually look like. These creatures are talked about more as of a spell effect with no associated spell than an actual being.
AD&D Irish Deer
These fall within the provenance of 'herd animals' and I assume their inclusion is to appeal to the pleistocene enthusiasts of the early D&D crowd.
A bizarre combination of 'evil clerics' and 'manta rays,' with some of them being level draining vampiric variants. Though no doubt one of my internet friends will be displeased to see me once again scorning the aquatic inhabitants of D&D, I cannot say I understand the appeal of these entities.
Sunset Realm So and So's
Imps were already discussed in the demons post, and while I am not opposed to a killer body-snatching brain, I don't think my implementation of such an entity would have anything in common with an Intellect Devourer. And as for the rest, no, I think not.
|I haven't decided how such a brain would enter the cranium yet though, so perhaps this Yuban apprentice screams in horror at the questionable perspective rather than the brain|