Bloodworm: so it loses 5 hp but can gain 10? I think a better mechanic would be that if it drains blood, then 1) it does not lose 5 hp that round, and 2) it gains 5 HP. That way the HP values are not bouncing up and down too much independent of PC actions. But honestly I think the monster should have some other power - an encounter, a recharge, something. Since it's aquatic, perhaps something that lets it pull people under water. Otherwise it just stands in one place and everyone hacks at it and it does nothing unique after round 1 (just more damage).
Anyways, I just wonder what you're pairing the tunnel worm with in an encounter.
I do have one nitpick with the statblock: you say if the target PC is adjacent to the worm after the pull, the worm grabs it - the only instance this would not be the case is a dwarf, so why not just say 'pull 3 and grab'?
Or, well, crouch 4 squares away from the burrow and shoot into the hole.After the tunnel worm bites-and-releases its target, the pcs have three options: 1. Stand around its tunnel and let it keep using its best abilities; 2. Move out of its reach and try to lure it out; or 3. Try to send some small pcs into the tunnel after it.
Anyways, I just wonder what you're pairing the tunnel worm with in an encounter.
I do have one nitpick with the statblock: you say if the target PC is adjacent to the worm after the pull, the worm grabs it - the only instance this would not be the case is a dwarf, so why not just say 'pull 3 and grab'?