El mundo de Cómo entrenar a tu dragón está lleno de criaturas peculiares. El cremallerus espantosus (hideous zippleback en inglés) es el primero de ellos que he querido describir en términos del sistema d20.
NE Large dragon (earth)
AC 22, touch 11, flat-footed 20 (+2 Dex, +11 natural, –1 size)
hp 115 (10d12+50)
Fort +12, Ref +9, Will +7
Immune paralysis, sleep; Resist electricity 10, fire 10
Speed 30 ft., burrow 20 ft., fly 60 ft. (average)
Melee 2 bites +15 (2d6+9/19–20 plus 1d10 electricity)
Space 10 ft.; Reach 10 ft.
Special Attacks volatile breath, savage bite
Str 22, Dex 15, Con 21, Int 13, Wis 11, Cha 12
Base Atk +10
Feats Dodge, Mobility, Spring Attack, Combat Expertise, Whirlwind Attack
SQ speed surge, flammable
Environment warm hills
Organization solitary, pair, or rampage (3–12)
Volatile Breath (Ex) A hideous zippleback can breathe a cone of flammable gas as a breath weapon. As a swift action, it can ignite the gas producing an electrical spark with its other head. When ignited, the gas explodes, dealing 9d6 points of fire damage in the area of the cone (Reflex half DC 20). If not ignited, the gas confuses all creatures in the area of effect that breathe it in before the gas dissipates at the start of the dragon's next turn. This confusion last for 1d4 rounds (Fortitude DC 15). It can use this ability once every 1d6 rounds, during which the dragon cannot ignite its volatile breath. The save DCs are Constitution-based, and the confusion save DC has a –5 racial penalty.
Flammable (Ex) A hideous zippleback’s scales catch on fire easily. It gets no saving throw when catching on fire and any spell or ability that deals at least 1 point of fire damage to it automatically sets it on fire. Creatures that attack or are attacked by a hideous zippleback on fire take 1d6 points of fire damage. A hideous zippleback can use its volatile breath ability to set itself on fire as a standard action.
Savage Bite (Ex) A hideous zippleback applies 1-1/2 times its Strength modifier to damage dealt with its bite attack, and it threatens a critical hit on a 19–20.
Speed Surge (Ex) Three times per day as a swift action, a hideous zippleback can draw on its draconic heritage for a boost of strength and speed that allows it to take an additional move action that round.