Thessalmonsters are nocturnal predators that resemble a cross between an eight–headed hydra and another monster. The true origin of the thessalmonster lies shrouded in mystery, but many sages speculate the creature is the result of an arcane experiment gone awry involving an ancient thessalhydra and other monsters. Thessalmonsters are a combination of a thessalhydra and another creature. Thessalmonsters resemble hydras, complete with reptilian torso and eight serpentine heads in front. Some thessalmonsters retain the base creature’s head while others lose it and have it replaced with a central maw filled with serrated teeth.
“Thessalmonster” is an inherited template that can be added to any magical beast (referred to hereafter as the base creature) with 5 or more HD except a hydra. A thessalmonster retains all the base creature’s statistics and special abilities except as noted here.
CR: Same as the base creature +3.
Size and Type: The base creature’s type changes to aberration. Its size increases to Large if the base creature is Medium or smaller, or by one category if the base creature is Large or larger. Do not recalculate base attack bonus, skill points or base saves.
Armor Class: Same as the base creature plus any adjustment for size increase (see the Pathfinder Roleplaying Game Bestiary).
Speed: Same as the base creature or 40 ft., whichever is better. If the base creature can fly it loses this ability. The base creature retains all other modes of movement.
Attacks: A thessalmonster retains all the attacks of the base creature and gains eight secondary bite attacks with its serpentine heads. Additionally, it gains a bite attack with its primary head (if it didn’t already have one) or central maw.
Further, 50% of thessalmonsters have a pincer-like tail and gain a tail slash attack.
A thessalmonster has bite attacks (and possibly a tail slash) in addition to the attacks of the base creature. Damage for its bite attacks and tail slash are based on the thessalmonster’s size from the table below. Creatures that have other kinds of natural weapons retain their old damage values or use the ones below, whichever is better.
Space/Reach: Large thessalmonsters have 10 ft/5 ft.; Huge 15 ft./10 ft.; Gargantuan 20 ft./15 ft.; and Colossal 30 ft./20 ft.
Special Attacks: A thessalmonster retains all the special attacks of the base creature, and also gains those described below. Saves have a DC of 10 + 1/2 thessalmonster’s HD + thessalmonster’s Con modifier unless noted otherwise.
Each of a thessalmonster’s serpentine heads drips corrosive acid. Any bite attack deals 1d6 points of acid damage (in addition to normal bite damage). Further, 50% of thessalmonsters deal acid damage with any other bite attack the base creature has (acid damage equal to the damage shown on the table above). A thessalmonster whose primary head is replaced with a central maw automatically deals acid damage with a bite from its maw.
A thessalmonster with a tail can grab an opponent up to one size smaller with a successful tail slash attack. It can then attempt a grapple check as a free action without provoking an attack of opportunity. If it wins the grapple check, the thessalmonster establishes a hold and can constrict.
A thessalmonster that does not already possess a breath weapon or spit type special attack can spit a stream of acid in a 40-foot line that deals 4d6 points of acid damage. A successful Reflex save reduces the damage by half. This acid originates from the thessalmonster’s primary head or central maw and can be used once per day.
Special Qualities: A thessalmonster gains the following special qualities:
Though a thessalmonster cannot be killed by severing all of its serpentine heads, doing so prevents them from attacking and can assist in slaying its body. Any attack that is not an attempt to sever a head affects the body, including area attacks or attacks that cause piercing or bludgeoning damage. To sever a head, an opponent must make a sunder attempt with a slashing weapon targeting a head.
A head is considered a separate weapon with hardness 0 and hit points equal to the thessalmonster’s HD. To sever a head, an opponent must inflict enough damage to reduce the head’s hit points to 0 or less. Severing a head deals damage to the thessalmonster’s body equal to the thessalmonsters’s current HD. A thessalmonster can’t attack with a severed head, but takes no other penalties.