I think this is it.
I wish I could remember who I stole this from it is a great idea!
I hope I am not doing anything wrong by posting it, I am always shaky on netiquette.
I couldn't find the link and I couldn't figure out how to attatch a word file so this is pretty long. Sorry.
CREATING A XENOMORPH
“Xenomorph” is a template that can be added to any corporeal, aberration, animal, beast, dragon, fey, giant, humanoid, magical beast, monstrous humanoid, shapechanger, or vermin that is small-sized or larger (referred to hereafter as the “base creature”). The creature’s type becomes “beast.” It uses all the base creature’s statistics and special abilities except as noted here.
Hit Dice: Gains an additional 5 hit dice over and above the base creatures total, plus the xenomorph’s size increases to the medium size category (if larger no size increase is gained).
Speed: Because of their exotic physiology xenomorphs gain +10 feet in addition to the base creature’s speed. The xenomorphs are excellent swimmers with a speed equal to have their walking rate rounded down to the nearest 10 ft increment, with a good maneuverability underwater. If the base creature already possesses a swimming speed add 10 feet to that value.
AC: Natural armor improves by +6.
Damage: Xenomorphs have bite, jaw (inner mouth), claw and tail attacks. If the base creature does not have these attack forms, use the damage values in the table below. Otherwise, use the values below or the base creature’s damage, whichever is greater.
Size Bite Damage
Jaw Damage
Claw Damage
Tail Damage
Medium
1d6
1d8
1d8
1d8
Large
1d8
2d6
2d6
2d6
Huge
2d6
2d8
2d8
2d8
Gargantuan
2d8
2d12
4d6
4d6
Colossal
4d6
4d12
4d8
4d8
Special Attacks: A Xenomorph retains all the special attacks of the base creature except for any spell casting or psionic abilities, and gains an acid spit attack.
Acid Spit (Ex): By making a ranged touch attack the xenomorph can spit a line of acid that deals 2d6 damage up to 30 ft away.
Special Qualities: A xenomorph has all the special qualities of the base creature plus acidic blood, blindsight, a form of regeneration, spider climb, and a survival instinct.
Acidic Blood (Ex): Perhaps the xenomorph's most deadly feature is its acid blood. If a slashing, piercing, or bludgeoning attack wounds a xenomorph, the xenomorph’s concentrated acidic blood sprays outward from the wound. The blood sprays outward (45 degree towards the attacker) to a radius of feet equal to the damage it received (1 hp damage = 1 ft radius, 2 hp damage = 2 ft radius, 3 hp damage = 3 ft radius, etc) up to a maximum radius of 10 feet. Anyone caught within this radius must make a reflex save (DC equal to 10 plus ½ the damage inflicted) successfully or suffer 3d8 hp acid damage, another 2d8 acid damage the second round, and another d8 acid damage third round. If the attacker was stupid enough to have used a natural weapon (fist, feet, claw, teeth, etc), attacker immediately suffers an additional 3d8 hp acid damage, another 2d8 acid damage the second round, and another d8 acid damage third round. The acid is extremely corrosive, eating up normal weapons and armor within seconds, even rocks. Magical weapons and armor dissolve at the rate of +1 per round instead of seconds. When a xenomorph is killed, it melts into a thick puddle of acid. The puddle of acid eats away at the ground until oxidizing completely in 1d4+3 rounds, leaving behind nothing more than a small amount of skin, skeleton, and a rough crater about 2 feet deep.
It is never a good idea to overkill a xenomorph, or you'll be the one getting overkilled. If a xenomorph's hit point is reduced to -1 or lower, its body explodes upon destruction, spraying all it's deadly internal organs and fluids outward. Their acidic blood sprays outward in all directions to a radius of feet equal to the damage it received (1 hp damage = 1 ft radius, 2 hp damage = 2 ft radius, 3 hp damage = 3 ft radius, etc) up to a maximum radius of 10 feet. Anyone caught within this radius must make a reflex save (DC equal to 10 plus ½ the damage inflicted) at +1 per hit point the xenomorph was overkilled, or immediately suffer 6d8 acid damage the first round, 5d8 acid damage the second round, 4d8 acid damage the third round, and so on down to d8 damage.
Regenerate (Ex): A xenomorph has the ability to regenerate itself by eating the biomaterial of other living creatures. It can regenerate 1 hit point per pound of matter consumed in this fashion. This is a full round action.
Survival Instinct: The xenomorphs have a strong survival instinct as part of their special intelligence. In combat, they combine cunning and tactics with incredible agility, speed, and strength. The ferocity of these monsters in combat is frightening! Xenomorphs attack without fear of death, and kill for sheer pleasure. A xenomorph never suffers from a lack of morale in combat. If a battle is turning against them, they will make a tactical retreat, only to return with improved strategy and greater force. They are relentless in their pursuit of fleeing prey. When angered, hurt, or destroyed, the xenomorph lets out a terrible ear-piercing shriek or roar.
All xenomorphs hate fire, but suffer no weaknesses from it. In fact, they are extremely resistant to adverse environmental conditions such as cold and heat, and suffer only quarter damage from such attacks both magical and non-magical. Xenomorphs are even completely immune poisons and mind-based magic, including being unaffected by most illusions and psionic abilities. Their exoskeleton has partial immunity to acids (Acid Resistance 16).
Spider Climb (Ex): They are able to scale walls and ceilings with phenomenal ease and their speed is unhampered by tight spaces like airshafts and pipes. Xenomorphs are also excellent swimmers. Xenomorphs can spider climb at will as per the spell of the same name cast by an 18th level sorcerer but with an unlimited duration.
Blindsight (Ex): Gains blindsight 40 ft radius.
Abilities: Increase from the base creature as follows: Str +4, Dex +6, Con +2, Int +2 (Max of 6), Wis +0, Cha -4.
Skills: Same as the base creature plus the xenomorph’s gain a +6 to their Climb, Hide, Move Silently and Swim checks. Xenomorphs have no use for skills that require thought to be put into them such as craft, diplomacy, knowledge and other similar skills, as a result all skills that require complex thought are dropped.
Feats: A xenomorph gains Combat Reflexes, Dodge, Improved Initiative, Lightning Reflexes, Weapon Finesse (Claw, Tail & Bite), and Multiattack, assuming the base creature meets the prerequisites and doesn’t already have these feats. Also a xenomorph possesses no weapon-related feats other than the weapon finesse feats listed above.
Climate: Same as the base creature.
Organization: Solitary or in packs of 2 to 5.
Challenge Rating:
5 - 8 HD = Base Creature CR +3
9 - 14 HD = Base Creature CR +2
15+ HD = Base Creature CR +1
Treasure: None.
Alignment: Always Neutral.
Advancement: None.
SAMPLE XENOMORPHS
Xenomorphic Troll
Large Beast
Hit Dice: 11d10+77 (137 hp)
Initiative: +9 (+5 Dex, +4 Improved Initiative)
Speed: 40 ft, swim 20 ft (good maneuvering)
AC: 27 (-1 size, +5 Dex, +13 Natural)
Attacks: 2 Claws +15, Bite +13, Tail +13, Jaw +13
Damage: Claw 2d6+8, Bite 1d8+8, Tail 2d6+8, Jaw 2d6+8
Face/Reach: 5 ft by 5 ft / 10 ft
Special Attacks: Rend 2d6+8, Acid Spit
Special Qualities: Blindsight 40 ft, Regeneration 5, Scent, Darkvision 90 ft, Acidic Blood, Regenerate, Spider Climb, Survival Instinct
Saves: Fort +14, Ref +14, Will +2
Abilities: Str 27, Dex 20, Con 25, Int 6, Wis 9, Cha 2
Skills: Climb +14, Hide +7, Listen +5, Move Silently +11, Spot +5, Swim +14
Feats: Alertness, Combat Reflexes, Dodge, Improved Initiative, Lightning Reflexes, Multiattack, Weapon Finesse (Claw), Weapon Finesse (Bite), Weapon Finesse (Tail).
Climate/Terrain: Any Land, Aquatic, and Underground
Organization: Solitary or in packs of 2 to 5.
Challenge Rating: 7
Treasure: None
Alignment: Always Neutral
Advancement: None
Xenomorphic Brown Bear
Large Beast
Hit Dice: 11d10+55 (115 hp)
Initiative: +8 (+4 Dex, +4 Improved Initiative)
Speed: 50 ft, swim 20 ft (good maneuvering)
AC: 24 (-1 size, +4 Dex, +11 Natural)
Attacks: 2 Claws +17, Bite +15, Tail +15, Jaw +15
Damage: Claw 2d6+10, Bite 2d8+10, Tail 2d6+10, Jaw 2d6+10
Face/Reach: 5 ft by 10 ft / 5 ft
Special Attacks: Improved Grab, Acid Spit
Special Qualities: Blindsight 40 ft, Scent, Acidic Blood, Regenerate, Spider Climb, Survival Instinct
Saves: Fort +12, Ref +13, Will +4
Abilities: Str 31, Dex 19, Con 21, Int 4, Wis 12, Cha 2
Skills: Climb +16, Hide +6, Listen +4, Move Silently +10, Spot +7, Swim +22
Feats: Combat Reflexes, Dodge, Improved Initiative, Lightning Reflexes, Multiattack, Weapon Finesse (Claw), Weapon Finesse (Bite), Weapon Finesse (Tail).
Climate/Terrain: Any Land, Aquatic, and Underground
Organization: Solitary or in packs of 2 to 5.
Challenge Rating: 6
Treasure: None
Alignment: Always Neutral
Advancement: None
Xenomorphic Ancient Red Dragon
Gargantuan Beast
Hit Dice: 39d10+390 (604 hp)
Initiative: +7 (+3 Dex, +4 Improved Initiative)
Speed: 50 ft, 210 ft (clumsy), swim 20 ft (good maneuvering)
AC: 48 (-4 size, +3 Dex, +39 Natural)
Attacks: 2 Claws +41, Bite +39, 2 Wings +39, Tail +39, Jaw +39
Damage: Claw 4d6+8, Bite 4d6+16, Wing 2d6+8, Tail 4d6+24, Jaw 2d12+16
Face/Reach: 20 ft by 40 ft / 15 ft
Special Attacks: Acid Spit, Breath Weapon, Frightful Presence 300 ft (Will Save DC 34), Crush (4d8+24 damage), Tail Sweep (2d8+24 damage)
Special Qualities: Fire Subtype, DR 15/+2, Blindsight 300 ft, Darkvision 1000 ft, Acidic Blood, Regenerate, Spider Climb, Survival Instinct
Saves: Fort +31, Ref +26, Will +22
Abilities: Str 43, Dex 16, Con 31, Int 6, Wis 25, Cha 20
Skills: Balance +7, Bluff +39, Climb +56, Escape Artist +39, Hide +31, Intimidate +7, Listen +43, Move Silently +43, Search +32, Spot +43, Swim +16, Tumble +41
Feats: Alertness, Combat Reflexes, Dodge, Flyby Attack, Hover, Improved Initiative, Iron Will, Improved Critical (Claw), Lightning Reflexes, Power Attack, Snatch, Multiattack, Weapon Finesse (Claw), Weapon Finesse (Bite), Weapon Finesse (Tail), Wingover.
Climate/Terrain: Any Land, Aquatic, and Underground
Organization: Solitary or in packs of 2 to 5.
Challenge Rating: 23
Treasure: None
Alignment: Always Neutral
Advancement: None
Xenomorphic Ettercap
Medium Beast
Hit Dice: 10d10+20 (77 hp)
Initiative: +10 (+6 Dex, +4 Improved Initiative)
Speed: 40 ft, climb 40 ft, swim 20 ft (good maneuvering)
AC: 23 (+6 Dex, +7 Natural)
Attacks: 2 Claws +13, Bite +11, Tail +11, Jaw +11
Damage: Claw 1d8+2, Bite 1d8+2 and poison, Tail 1d8+2, Jaw 1d8+2
Face/Reach: 5 ft by 5 ft / 10 ft
Special Attacks: Poison, Web, Acid Spit
Special Qualities: Low-light Vision, Blindsight 40 ft, Scent, Acidic Blood, Regenerate, Spider Climb, Survival Instinct
Saves: Fort +9, Ref +15, Will +5
Abilities: Str 14, Dex 23, Con 15, Int 6, Wis 15, Cha 4
Skills: Climb +16, Hide +9, Listen +10, Move Silently +12, Swim +8
Feats: Combat Reflexes, Dodge, Improved Initiative, Lightning Reflexes, Multiattack, Weapon Finesse (Claw), Weapon Finesse (Bite), Weapon Finesse (Tail).
Climate/Terrain: Temperate and Warm Forests
Organization: Solitary or in packs of 2 to 5.
Challenge Rating: 6
Treasure: None
Alignment: Always Neutral
Advancement: None
