Megalodon

One of the largest predators in the world, a megalodon defers to dragons and little else. Large enough to devour an entire whale, the megalodon gives even hardened sailors nightmares.

A megalodon is normally 55 to 65 feet long, and it weighs between 10 to 60 tons. Rumors of individual megalodons reaching a length of 80 to 90 feet cannot be confirmed.

Combat

Megalodons attack anything they perceive to be edible⁠—​including each other. They can leap as high as 40 feet out of the water to snap at low-flying rocs and small dragons. They bite with their powerful jaws and can swallow smaller creatures.

Improved Grab (Ex): If a megalodon 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 +40). If it gets a hold, it can try to swallow on the next round. Alternatively, the megalodon has the option to conduct the grapple normally, or simply use its jaws to hold the opponent (–⁠20 penalty on grapple check, but the megalodon is not considered grappled). In either case, each successful grapple check it makes during successive rounds automatically deals bite damage.

Swallow Whole (Ex): A megalodon can swallow a single creature that is at least one size category smaller than itself by making a successful grapple check (grapple bonus +40), provided it already has that opponent in its mouth (see Improved Grab, above). Once inside the megalodon, the opponent takes 2d8+10 points of bludgeoning damage plus 1d8+4 points of acid damage per round from the megalodon’s gullet. See Swallow Whole for escape methods and other information. A megalodon’s gullet has an AC of 16 and 25 hit points. A Gargantuan megalodon’s gullet can hold 2 Huge, 8 Large, 32 Medium-size, or 128 Small or smaller opponents.

Keen Scent (Ex): A megalodon notices creatures by scent within a 180-foot radius and detects blood in the water at a range of up to one mile.

Skills: A megalodon can move through water at its swim speed without making Swim checks. It has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. The creature can always can choose to take 10 on a Swim check, even if distracted or endangered. The creature can use the run action while swimming, provided it swims in a straight line.

Source: Monster Manual II, page 147. This creature’s statistics block has been updated to version 3.5 as given in the D&D® V.3.5 Accessory Update for Monster Manual II.