Elasmosaurus (CR 7)

Huge Animal
Alignment: Always neutral
Initiative: +2 (Dex); Senses: low-light vision, scent, Listen +4, and Spot +9


AC: 13 (-2 size, +2 Dex, +3 natural), touch 10, flat-footed 11
Hit Dice: 10d8+66 (111 hp)
Fort +15, Ref +9, Will +4
Speed: 20 ft., swim 50 ft.
Space: 15 ft./10 ft.
Base Attack +7; Grapple +23
Attack: Bite +13 melee
Full Attack: Bite +13 melee
Damage: Bite 2d8+12
Special Attacks/Actions: -
Abilities: Str 26, Dex 14, Con 22, Int 2, Wis 13, Cha 9
Special Qualities:
Feats: Dodge; Great Fortitude; Toughness (2)
Skills: Hide +4*, Listen +4, Spot +9, and Swim +16
Advancement: 11-20 HD (Huge)
Climate/Terrain: Warm aquatic
Organization: Solitary or pair
Treasure: None

Source: Monster Manual

Combat

An elasmosaurus is aggressive and attacks anything it notices. The creature is strong, fast, and highly maneuverable, able to turn quickly and lunge at prey. When hunting, it travels with its head out of the water, snapping down quickly to seize prey.