Cleon
Legend
This caught my attention. In order to complete its full attack action against a grappled (or any other) opponent, even with Improved Grab and Pounce, the Deinonychus would have to make its grapple check at -20 to hold the opponent while not being considered grappled itself. Otherwise, as soon as it grabs the opponent, it can only take actions normally allowed in a grapple, and only at the beginning of its NEXT turn. (An exception would be a talon-stab, if you consider it the same as a rake attack - it gets to make one for free as soon as it grapples).
I think it's OK, since its Pounce is basically the same as a big cat's, which allows for a full attack without a grapple check penalty.
As it is now, I think it, and all the Maniraptors, are doing way too much damage. Velociraptor is doing 2d6+2d3+1d8 damage on a charge. In my opinion the talons should be exclusively talon-stab attacks, not part of their regular attack action unless they grapple or charge.
I make it 1d6+2d3+1d8, where's the 2d6 from? Regular weapons only get an attack bonus on a charge, not double damage.
It is a lot of damage, but I wanted to keep it in line with the SRD big cats - a 3HD leopard does 1d6+3+4d3+4 (average 18.5), is about midway between my 3HD Dromaeosaurus's 1d6+1+2d3+1d8+1 (av. 14) and 4HD Deinonychus's 1d8+2+2d4+2+2d6+3 (av. 23.5), a tiger's 2d8+12+2d6+3+2d8+6 pounce (av. 46!) is more or less exactly the same as my Utahraptor's 2d6+6+2d6+6+3d6+9 (45.5), and considerably more than the 6HD Achillobator's 2d4+4+2d4+4+2d8+6 pounce (av. 33).
So I think the damage is in keeping with the sample creatures I'm using as a baseline, it's not my fault the sample creatures are too vicious!
Anyhow, as I said earlier I think an easy solution is just to say a more realistic version of a Maniraptor uses the stats of the next stage down (Dromaeosaurus for Deinonychus, Achillobator for Utahraptor, et cetera), and the provided stats take after the prehistoric monsters of cinema, pulp-fiction and comic books as much as they do nature.
EDIT: Another thought. By default, Improved Grab only works on smaller opponents. If you want it to affect larger opponents too, you have to specify.
That's a good point, I suspect everyone thinks it just follows normal grapple size limits. I'd better amend it.