All along the river, Lake Hylia, Lake Hylia Temple
Purple in color with a large spiral shell over their head. They have 8 tentacles At the base of their body. Their giant eyes allow them to have a large field of view, allowing them to see the player even from the side.
They like to sneak up on unsuspecting travelers and then blast them with rocks. They usually just try to annoy the hell out of those passing by, but do get aggressive from time to time.
All projectile weapons are able to kill them. The exception is the boomerang which stuns, and the ice arrow which freezes them into a block to use as as stepping stone. Roc's Cape must be used to jump to it. When the player approaches, they hide underwater. This forces the player to have to use projectiles.
.5HP to player, 1HP to self (2HP with properly timed bash) Spits out a rock that can be reflected with a shield bash. The bash will reflect the same distance regardless of the timing. However, a carefully timed bash will result in a faster reflection, dealing twice as much damage.