The Monster Manual lists two variants of the beholder: the death tyrant, a more powerful, undead variant; and the spectator, a less powerful, not-really-evil variant. Volo’s Guide to Monsters lists three: the death kiss, the gauth and the gazer. Together, these are referred to as “beholder-kin.” All three variants are evil.
The death kiss is the most powerful of the three, though not as powerful as a standard beholder. In lieu of ray-projecting eyestalks, its body is covered with long, waving tentacles that end in spines and toothy mouths. It has the extremely silly feature Lightning Blood (which I can’t even type without laughing ruefully), which inflicts lightning damage against any opponent that strikes it with a piercing or slashing weapon. That’s right: Its blood is electrically charged. This is ridiculous even for an aberration. I mean, I can almost buy the flavor text explanation, “A death kiss survives solely on ingested blood, which it uses to generate electrical energy inside its body,” with the usual suspension of disbelief that Dungeons and Dragons demands, but to suggest that the death kiss’s blood itself is what carries the stored electrical charge, and not some other organ in the death kiss’s body . . . whatever, man, I can’t even with this. You hit it, you get shocked. That’s what it says.