Olaf the Stout
Legend
eamon said:Almost!
Improved Grab:
If the creature does not constrict, each successful grapple check it makes during successive rounds automatically deals the damage indicated for the attack that established the hold. Otherwise, it deals constriction damage as well (the amount is given in the creature’s descriptive text).
So, you correctly judged that a choker that hits deals 1d3+3 damage, and if gains a hold, it deals 1d3+3 damage as well for a total of 2d3+6. But, on each successful grapple check thereafter, the choker deals damage per the weapon used with improved grab (1d3+3), and/i] constrict: another 1d3+3! So, each successful grapple check deals 2d3+6 damage.
So in a suprise round a Choker could deal 4d3+12 points of damage if it succeeded on all of its rolls.
So close!

Thanks for the pick-up eamon. You are correct. I missed the second lot of constriction damage.
It is interesting to note then that, as Hypersmurf stated earlier, if a Choker hits and successfully grapples on its first attack, a standard attack will then do as much damage as a full attack could since it can't get its second tentacle attack in (without taking a -20 on grapple checks).
This thread has really helped me to better understand how monsters with Improved Grab work. Thanks guys!

Olaf the Stout