Well, Krish, I've been out of town, and there's not much too interesting to do with ceratopsians, but here's a little something I've had on the back burner for some time. It's not a dinosaur, but it's old, big and reptilian.
Lioplureodon
Colossal Animal (Aquatic)
Hit Dice: 20d8+ 200 (290 hp)
Initiative: +5
Speed: Swim 40ft
AC: 19 (-8 size, +1 Dex, +16 natural)
Base Attack/Grapple: +15/+48
Attacks: Bite +24 melee, 2 fin slaps +22 melee
Damage: Bite 4d8+17 (19-20 x2), fin slap 2d6+8 (19-20 x2)
Face/Reach: 40ft/15ft
Special Attacks: Improved grab, swallow whole
Special Qualities: Blindsight 120ft
Saves: Fort +24, Ref +13, Will +9
Abilities: Str 45, Dex 13, Con 30, Int 2, Wis 16, Cha 6
Skills: Hide +9, Move Silently +15
Feats: Great Fortitude, Improved Critical (bite, fin slap), Multiattack, Skill Focus (Move Silently) Weapon Focus (bite, fin slap)
Climate/Terrain: Warm or temperate ocean
Organization: Solitary or pair
CR: 11
Treasure: None
Alignment: Always neutral
Advancement: 21-60 HD (Colossal)
The largest creature in the prehistoric ocean, the lioplureodon is a short-necked plesiosaur supremely adapted to hunting other aquatic reptiles. A liopluerodon resembles a mammoth reptilian whale over eighty feet long. Its four wing-like paddles stretch over twenty feet long, and its head composes about one third of its body length.
Combat
Surprisingly stealthy for a creature of its size, a liopluerodon prefers to ambush its prey from below, grabbing it in their massive jaws, shaking it violently, and then swallowing the still living creature for digestion. They are fiercely territorial, and will attack any intruders, such as ships, without provocation.
Blindsight (Ex): Utilizing echolocation, a liopluerodon can discern objects and creatures within 120 feet. It does not usually need to make Spot or Listen checks to notice creatures within the range of its blindsight. If deafened, or within the radius of a silence spell, the liopluerodon has to rely on it weak vision (maximum range 60 feet)
Improved Grab (Ex): Whenever a liopluerodon hits an opponent of Huge or smaller size with its bite attack, it can make a grapple check without receiving an attack of opportunity (grapple bonus +48). It can choose to conduct the grapple normally, or to only hold its opponent in its jaws (-20 penalty to grapple checks, but the liopluerodon is not considered grappled). A grappled creature takes bite damage every round, and the liopluerodon can choose to swallow its foe whole.
Swallow Whole (Ex): By making a successful grapple check, a liopluerodon may swallow a held foe whole. Once swallowed, a victim takes 2d8+10 points of bludgeoning damage plus 3d6 acid damage every round until it escapes or dies. A successful grapple check allows the creature to climb out of the stomach and into the lioplurodon’s mouth, where another grapple check is required to get free. Alternatively, the swallowed creature can escape by cutting its way out with either claws or a light slashing or piecing weapon. Dealing at least 50 points of damage (AC 20) in this fashion allows the creature to escape. Once a single swallowed creature exits, muscular action closes the whole; another swallowed creature must cut its way out as well. A liopluerodon’s stomach can hold 2 Huge, 4 Large, 16 Medium-sized, 32 Small or 64 Tiny or smaller creatures.
Skills: A liopluerodon receives a +4 racial bonus to all Move Silently checks.
Demiurge out.