Ok, noted.  Rolling for you, in that case; the DC to tumble is +10 since you're moving at full speed instead of half speed, and a total of 17 (rolled a 9) isn't enough.<br/><br/>So, I have to figure out how to do opportunity attacks with these guys.  I'm thinking something along the lines of, the monster can make a grapple with all of its available tentacles; tentacles that just respawned on the monster's last turn still can't act.<br/><br/>Oh, and it got a natural 20 for its opportunity grapple... >.>