Allosaurus (CR 7)
Alignment: Always neutral
Initiative: +1 (Dex); Senses: darkvision 60 ft., low-light vision, scent, Listen +10, and Spot +11
AC: 14 (-2 size, +1 Dex, +5 natural); touch 9, flat-footed 13
Hit Dice: 10d8+33 (78 hp)
Fort +10, Ref +8, Will +5
Speed: 50 ft.
Space: 15 ft./15 ft.
Base Attack +7; Grapple +24
Attack: Bite +12 melee and 2 claws +7 melee
Full Attack: Bite +12 melee and 2 claws +7 melee
Damage: Bite 2d8+7, claw 2d4+3
Special Attacks/Actions: Improved grab, rake 2d8+3, swallow whole, trample 5d8+10
Abilities: Str 24, Dex 12, Con 17, Int 2, Wis 15, Cha 11
Feats: Alertness; Run; Toughness; Track
Skills: Listen +10 and Spot +11
Advancement: 11-20 HD (Huge); 21-30 HD (Gargantuan)
Climate/Terrain: Warm forest, hills, plains, and marsh
Organization: Solitary or pair
Monster Manual II
Allosaurus eats everything it can catch. If its prey is too big to swallow whole, the dinosaur latches on with its powerful jaws and begins raking until the creature is dead.
Improved Grab (Ex): If allosaurus hits an opponent that is at least one size category smaller than itself with a bite attack, it deals normal damage and attempts to start a grapple as a free action without provoking an attack of opportunity (grapple bonus +22). If it gets a hold, it can attempt to rake in the same round, and the next round it can try to swallow the opponent. Alternatively, allosaurus has the option to conduct the grapple normally, or simply use its jaws to bold the opponent (-20 penalty on grapple check, but allosaurus is not considered grappled). In either case, each successful grapple check it makes during successive rounds automatically deals bite damage and allows another rake attempt.
Rake (Ex): On any round that allosaurus has a hold on an opponent (see Improved Grab, above), it can make two rake attacks (+12 melee) with its hind legs for 2d8+3 points of damage each. Allosaurus can also attempt to rake when it pounces on an opponent.
Swallow Whole (Ex): Allosaurus can swallow a grabbed opponent that is at least two size categories smaller than itself by making a successful grapple check (grapple bonus +22). Once inside the gullet, the opponent takes 2d8+12 points of Bludgeoning damage and 1d8 points of acid damage per round from the dinosaur's digestive juices. A successful grapple check allows the swallowed creature to climb out of the gullet and return to the mouth, where another successful grapple check is needed to get free. Alternatively, a swallowed creature can try to cut its way out with either claws or a light piercing or slashing weapon. Dealing at least 25 points of damage to the digestive tract (AC 20) in this way creates an opening large enough to permit escape. Once a single swallowed creature exits, muscular action closes the hole; thus, another swallowed opponent must cut its own way out. A Huge allosaurus's gullet can hold 1 Medium-size, 4 Small, 16 Tiny, or 64 Diminutive or smaller opponents.
Trample (Ex): As a standard action during its turn each round, allosaurus can trample opponents at least one size category smaller than itself. This attack deals 5d8+10 points of bludgeoning damage. A trampled opponent can attempt either an attack of opportunity at a -4 penalty or a Reflex save (DC 22) for half damage.
Scent (Ex): A dinosaur can detect approaching enemies, sniff out hidden foes, and track by sense of smell.