Blackwater Tentacle

You create a tentacle-shaped mass of blackwater, drawn from the deepest ocean trenches, to attack an enemy as you direct it.
The tentacle appears at a particular point within range and can't move from that location.
It attacks the opponent you designate once each round, starting with the round the spell is cast.
It has a reach of 20 feet (though it can't make attacks of opportunity).
Its attack bonus is equal to your caster level plus the ability modifier you would normally use to set the save DC (Wisdom for cleric or druid, Intelligence for wizard, Charisma for sorcerer).
The tentacle deals 2d8 + caster level (max.
+20) points of damage with a successful hit.
The tentacle never provides nor benefits from a flanking bonus.
Once a tentacle has been directed to attack a foe, it continues to do so until the spell is redirected to a new target (a move action).
The tentacle has 5 hit points per caster level and an AC of 10 + your caster level.
It automatically fails all saves.