I was looking at the monster entry for a Hangman Tree (http://www.d20pfsrd.com/bestiary/monster-listings/plants/hangman-tree) and it lists both Grab and Pull on its vine attack.
If it hits with its vine attack does it get to make both a grab and a pull combat maneuver check or does it have to pick one? If it succeeds on its grab isn't the pull completely redundant since grappling a creature automatically places them in a square adjacent to you?
Yes it can choose to do both.
Yes the pull is redundant if the grapple succeeds.
However if the grapple fails, and the pull succeeds, the target will move 5ft closer.
Ah, so the pull is more of a contingency. Still a bit redundant but not useless. Basically the baddie gets to roll more dice per turn to do nasty stuff to the players, which is always good. Or bad, depending on which side of the screen you're on.
Or let's just say it's more interesting.
You really don't want to be grappled by this tree: strangulation, swallow whole... its a nasty business. The "pull" is the least of the worries. I find it quite cute that it can grapple multiple targets without being considered grappled itself...that is effectively a +20 bonus to its grapple checks right there.
Advice to adventurers: Stay away. ;p