[Yakk]

Cute Crab. :)

Note that it takes a -20 on it's Grapple check if it tries to hold someone only using one tentacle.

Is there any point in noting that it is mindless?

You might want to include some semi-flavor text about the use of the carapace (ie, treasure) or remaining fluid.

It lacks any ability to attack things flying nearby -- in theory, a single archer flying 100' up kills this without taking a single point of damage.

Throwing? Rays? Being able to call down meteors? A jump-type move option every 1d4 rounds? The ability to make a single super-long tentacle? Flight?