How to read 2 claws in a Pathfinder monster stack block? [duplicate]

Question

An example of the monster I have a question over is a Crab, Giant. It's Melee looks like this:

2 claws +4 (1d4+2 plus grab)

I am wondering about the "2 claws" part. Does that mean the crab gets to strike twice with both its claws as a full round action, thus possibly rolling 1d4+2 twice? Or is the stat block saying the crab attacks with both of it's claws and together does only 1d4+2?

Also, what if the Melee looked like this:

2 claws +4 (1d4+2 plus grab), bite +5 (1d8+4)

Does the above melee line allow for three full attacks as a full round action? Or only two attacks?

I just started DMing for the first time and am trying to become prepared.

Answer 1

It does indeed have two separate claw attacks, at the same bonus and doing the same damage. Many creatures with two claws also have rend, which is bonus damage done if they hit with both claws in the same round.

You are also right that they only get both claw attacks if they take a full attack. On a standard action attack or charge (without the pounce special ability, where they can full attack on a charge) they only get one of their attacks.

The creature with two claws and a bite can take three attacks on a full attack (the claw/claw/bite dating all the way back to at least 2e), or can move and still take one of the three as a standard action (almost every creature with both claws and bite will choose the bite if they only get one.) A max-sized dragon can attack with claw/claw/bite/wing/wing/tail with a full attack.