Alright, got a weird one.
Last night, we were running this creature: https://www.d20pfsrd.com/bestiary/monster-listings/aberrations/yangethe/
Under it's ability "Feeding Tentacles": As a standard action, a yangethe can use its mouth tenta/cles to feed on a helpless creature or a creature it is currently grappling. In this case, if the yangethe hits with a melee touch attack, the feeding
Mechanically, this doesn't work, does it? The monster has grab (ex) but on anything other than a helpless target, you wouldn't be able to initiate the feed, would you not?
Think of this scenario - the Yangthe attacks as a standard action, free action grabs. It is unable to use it's "Feeding Tentacles"
Ah, ok so it has to be next turn...except, maintaining a grapple is a standard action....and the ability is a standard action.
Am I missing something? I feel like monsters run into these grapple issues all the time, but as deeply as I study the rules I can't find anything other than
"Do all your tentacle attacks, constrict, release, attack again." due to the flawed action economy of maintaining a grapple.
Maybe the argument could be made that you could do the feed as part of your full attack action but...that's pretty house-ruley.
Would love to hear people's thoughts.