It's always bugged me that, whilst D&D presents us with many giant-sized animals and insects, the snakes mostly seem to be just regular-sized snakes that exist today. Last night, I caught the UK screening of the Smithsonian Channel's Titanoboa documentary, and decided to scribble down some of the giant snake's characteristics and create some stats for it.
Titanoboa for Labyrinth Lord (all open content)
No. Enc.: 1 (1)
Movement: 60' (20')
Swim: 120' (40')
Armour Class: 5
Hit Dice: 10-12
Attacks: 2 (bite, constrict)
Hoard Class: None (see below)
Titanoboas are immense constrictor snakes, measuring 40-50 feet in length, with bodies 2-3 feet in diameter at the widest point (or more if they have just eaten). They live in warm, tropical climates and spend most of their time in the water. On land, their movement is slow, due to their colossal weight (2,500lbs).
In combat, a titanoboa will first use its bite attack and attempt to lock on to prey with its powerful jaws. If successful, it will then throw its coils around the creature and begin to constrict it. Once the prey has been crushed to death, the titanoboa will swallow it whole and digest it. A large meal for a titanoboa would be a 15-foot long, half-ton crocodile, which would take the snake up to a year to fully digest.
A titanoboa, will not have treasure of its own, but there is a chance of finding undigested valuables in the snake's stomach.