Cave Troll

The monster known as the "Cave Troll" is actually the Chupacabra, and is named as such in all japanese versions of the games in which it appears. The persistence of its mistranslation is odd, as other mis-named monsters from Castlevania: Symphony of the Night (Venus Weed/Alura Une, Karasuman/Malphas, Granfalloon/Legion) were eventually corrected. In all games in which they appear, Cave Trolls attack by sticking out their long tongues, somersaulting at the hero, somersaulting while whipping their tongues in a multi-hit attack, or by using a powerful electric field.

In Castlevania: Symphony of the Night, Cave Trolls appeared late in the game, but were not a particular threat. They are similar in Castlevania: Dawn of Sorrow, and their soul allows Soma to stick his tongue out at increasingly longer lengths. In Castlevania: Portrait of Ruin, Cave Trolls gained an immense amount of attacking power, and their somersault-tongue and electric field attacks essentially became instant kills on the player. This repeated in Castlevania: Order of Ecclesia, in which they became immensely powerful enemies, something worth noting as one of them can be found remarkably early in the game.

Castlevania: Dawn of Sorrow
The only two known locations of Cave Trolls in this game are in the room before the Rahab boss room in Subterranean Hell, and one of the unlockable rooms in the Wizardry Lab. They are not very powerful, and attack by either lashing out their tongues or by hitting you with an electric field if close enough. Their soul is even more useless, as it allows Soma Cruz to attack using his tongue. The attack is extremely limited due to being very short range, and it doesn't do a lot of damage if it does connect.