Does a wildshaped druid in the form of a dire wolf who carries out an attack plus trip provoke an attack of opportunity? How about as a tiger doing attack plus grab? If some one was to pounce would they also be able to follow it up with a grab? Financially do the natural animals who these attacks apply too provoke attacks of opportunity? One thing would like to note trip as far as I know is something that anyone can do but if they lack improved trip feat it triggers an attack of opportunity. In beast shape II it says you gain the creatures trip ability. Dire wolfs' do not have improved trip listed as a feat.

"When a creature with this special attack makes a charge, it can make a full attack (including rake attacks if the creature also has the rake ability)."

If you read the Trip ability in the Universal Monster Rules, you find this:

Trip (Ex) A creature with the trip special attack can attempt to trip its opponent as a free action without provoking an attack of opportunity if it hits with the specified attack. If the attempt fails, the creature is not tripped in return.

Format: trip (bite); Location: individual attacks.

The Grab special ability says:

Grab (Ex) If a creature with this special attack hits with the indicated attack (usually a claw or bite attack), it deals normal damage and attempts to start a grapple as a free action without provoking an attack of opportunity. Unless otherwise noted, grab can only be used against targets of a size equal to or smaller than the creature with this ability. If the creature can use grab on creatures of other sizes, it is noted in the creature's Special Attacks line. The creature has the option to conduct the grapple normally, or simply use the part of its body it used in the grab to hold the opponent. If it chooses to do the latter, it takes a –20 penalty on its CMB check to make and maintain the grapple, but does not gain the grappled condition itself. A successful hold does not deal any extra damage unless the creature also has the constrict special attack. If the creature does not constrict, each successful grapple check it makes during successive rounds automatically deals the damage indicated for the attack that established the hold. Otherwise, it deals constriction damage as well (the amount is given in the creature's descriptive text).

Creatures with the grab special attack receive a +4 bonus on combat maneuver checks made to start and maintain a grapple.

Format: grab; Location: individual attacks.

As you can see, a wildshaped druid performing one of these combat maneuvers does not provoke attacks of opportunity

If the wild shape grants the special ability (per the appropriate Beast Shape spell), you use the version as defined in the Universal Monster Rules.

So yes, a dire wolf wild shape form can trip as part of a bite without provoking an AOO.

What about taking the form of a Pachycephalosaurus would I get the:

Clobbering Charge (Ex)

"When a pachycephalosaurus hits a target with its slam attack at the end of a charge, it can initiate a bull rush as a free action to move the struck target back in the same direction as the dinosaur's charge. The pachycephalosaurus cannot move with the target of the bull rush. If a pachycephalosaurus scores a critical hit against a creature with its slam attack at the end of a charge, it also staggers the target for 1 round. If the victim succeeds at a DC 18 Fortitude save, the stagger effect is negated, but the victim still suffers the effects of the dinosaur's bull rush attempt. The save DC is Strength-based."

^I would think no to the above because as I understand it you do not gain things like powerful bite

Wild Shape (Su): "This ability functions like the beast shape I spell, except as noted here."

Beast Shape I: "If the form you assume has any of the following abilities, you gain the listed ability: climb 30 feet, fly 30 feet (average maneuverability), swim 30 feet, darkvision 60 feet, low-light vision, and scent."

Each step up in Wild Shape acts like another step of Beast Shape (or plant shape or whatever). Each of those tell you exactly which abilities you get. If it's listed, you get it, and it works like it says it does. If it's not listed, you don't get it.

For the Pachycephalosaurus, it's a large animal. That means you use Beast Shape II (or better). Since none of those spells mention Clobbering Charge (Ex), you don't get that ability.

^I like this response direct and to the point thanks!

Correct; you only get exactly what the spell says you get and to the amount it says you get it. Nothing else. This is different than previous editions and can appear to be somewhat weaker but so much more simple and easy to follow than 3.5's wild shaping.

I just got way sad Beast Shape does not have powerful charge listed...