Breath Weapon (Su): A wyrm can breathe a 60-foot-long, 5-foot-wide line of fire every 1d4 rounds as an attack action. Any creature in the line of fire takes 10d10 points of damage, or half damage if a Reflex save (DC 25) succeeds.
Improved Grab (Ex): To use this ability, a wyrm must hit with both claw attacks. If it gets a hold, it hangs on and stings. If a wyrm grabs a creature two or more size categories smaller, it automatically deals damage with both claws and its sting each round the hold is maintained. See Improved Grab.
Fling (Ex): A wyrm can drop a creature it has grabbed or use an attack action to fling it aside. A flung creature travels 30 feet and takes 3d6 points of damage. If the wyrm flings it while flying, the creature takes this amount or falling damage, whichever is greater.
Poison (Ex): A creature stung by a wyrm must succeed on a Fortitude save (DC 25) or take 2d6 points of temporary Constitution damage. After 1 minute has elapsed, the creature must succeed on a second save (DC 25) or take another 2d6 points of temporary Constitution damage.
Immunities (Ex): Wyrms are immune to sleep, hold, and paralysis effects.
Skill Bonus: Wyrms receive a +3 species bonus on Spot checks during daylight hours.
Wyrm (Adult): CR 17; Huge dragon; HD 19d12+114; hp 237; Mas 23; Init –2; Spd 20 ft., fly 60 ft. (poor), burrow 20 ft.; Defense 21, touch 6, flat-footed 21 (–2 size, –2 Dex, +15 natural); BAB +19; Grap +37; Atk +28 melee (1d8+10 plus poison, sting); Full Atk +28 melee (1d8+10 plus poison, sting), +26 melee (2d8+5, bite), +26 melee (2d6+5, 2 claws); FS 15 ft. by 15 ft.; Reach 10 ft.; SQ breath weapon, improved grab, fling, poison, scent, immunities, darkvision 60 ft.; AL evil; SV Fort +17, Ref +9, Will +12; AP 0; Rep +0; Str 31, Dex 7, Con 23, Int 6, Wis 12, Cha 10.
Advancement: 20–26 HD (Huge); 27–38 HD (Gargantuan); 39–45 HD (Colossal).
Wyrm (Hatchling): CR 6; Medium-size dragon; HD 7d12+14; hp 59; Mas 15; Init +0; Spd 20 ft., fly 60 ft. (poor), burrow 20 ft.; Defense 18, touch 10, flat-footed 18 (+8 natural); BAB +7; Grap +9; Atk +10 melee (1d4+2 plus poison, sting); Full Atk +10 melee (1d4+2 plus poison, sting), +4 melee (1d8+1, bite), +4 melee (1d6+1, 2 claws); FS 5 ft. by 5 ft.; Reach 5 ft.; SQ breath weapon (DC 15; 3d10 points of fire damage), improved grab, poison (save DC 15; initial and secondary 2d6 Con), scent, immunities, darkvision 60 ft.; AL evil; SV Fort +7, Ref +5, Will +6; AP 0; Rep +0; Str 15, Dex 10, Con 15, Int 6, Wis 12, Cha 10.