One of the great things about the 3rd Edition of Dungeons & Dragons is the ways in which the rules can be so easily customized to fit particular campaign settings. For one thing, along with the Open Game License, this opened the door for such third-party products as Skull & Bones, the inspiration for this blog. Another example of this is how existing monsters can be made more or less powerful, just by adding hit dice to them and modifying other stats.
Interlude: The Serpent
Detailed below is a sea serpent, based on the statistics for a giant constrictor snake, but extrapolated to a much bigger size. This creature could serve as a random encounter for any band of pirates or other travelers while making a voyage by sea. Alternately, undigested items found in its belly could provide a hook for an entire adventure, such as the skeleton of a nobleman that still clutches a sealed scroll tube containing an important message.
Hit Dice: 33d8+36 (184 hp)
Speed: 30 ft. (6 squares), climb 30 ft., swim 30 ft.
Armor Class: 14 (–4 size, +3 Dex, +5 natural), touch 9, flat-footed 11
Base Attack/Grapple: +8/+23
Attack: Bite +23 melee (2d8+10)
Full Attack: Bite +23/+18/+13 melee (2d8+10)
Space/Reach: 20 ft./15 ft.
Special Attacks: Constrict 2d8+10, improved grab
Special Qualities: Scent
Saves: Fort +15, Ref +17, Will +7
Abilities: Str 25, Dex 17, Con 13, Int 1, Wis 12, Cha 2
Skills: Balance +15, Climb +21, Hide +13, Listen +12, Spot +12, Swim +20
Feats: Alertness, Endurance, Great Fortitude, Improved Initiative, Improved Natural Armor, Improved Natural Attack (bite), Improved Natural Attack (constrict), Lightning Reflexes, Skill Focus (Hide), Snatch, Toughness
Environment: Warm forests
Challenge Rating: 13
Level Adjustment: —
Sea serpents are larger and more aggressive relatives of other giant constrictor snakes. Given their size, there aren't too many targets that they can't swallow. They lurk in deep water, rising to the surface when a ship passes and striking out at the sailors aboard it. If the resistance put up by a crew is not too damaging, they might linger for a while and feed on multiple victims; otherwise they slip away, sinking back into the depths.