Since they don't have ranks in both Dip/SM or Bluff/Intimidate, I'd prefer Skill Focus to one of the dual-skill feats. But I think two feats may be a bit of overkill also.
Drop Persuasive and I can get on board with that feat list. (Or, alternately go with Persuasive and pilfer a few ranks for Bluff.) For the last feat, maybe Alertness or Blind-Fight?
Found the "revised/official" mouther, BTW. It's in Lords of Madness and supposedly includes errata from the MM.
So, which one should we be using - the Swallow Whole Mouther or the Engulf Mouther from the 3.5 SRD? If I remember correctly, the Engulf version is the Monster Manual one, and the Swallow Whole is the Lords of Madness one.
Given the choice, I prefer the Engulf one, since it's a lot closer to the AD&D version of the Mouther. Oh, and it also has Blood Drain
per attached mouth, which is nasty.
3.5 SRD said:
Blood Drain (Ex): On a successful grapple check after grabbing, that mouth attaches to the opponent. It automatically deals bite damage and drains blood, dealing 1 point of Constitution damage each round. A mouth can be ripped off (dealing 1 point of damage) with a DC 12 Strength check or severed by a successful sunder attempt (the mouth has 2 hit points). A severed mouth continues to bite and drain blood for 1d4 rounds after such an attack. A creature whose Constitution is reduced to 0 is killed.
Engulf (Ex): A gibbering mouther can try to engulf a Medium or smaller opponent grabbed by three or more mouths. The opponent must succeed on a DC 14 Reflex save of fall and be engulfed. In the next round, the mouther makes twelve bite attacks instead of six (each with a +4 attack bonus). An engulfed creature cannot attack the mouther from within. The previously attached mouths are now free to attack others. The save DC is Strength-based and includes a +2 racial bonus.