Rat, Giant and Otherwise
Potion of Rattiness- Causes your front teeth to grow, rodentlike. Not great for biting, but allows gnawing through things about as well as a dagger. You must gnaw on things to prevent your teeth from growing too much.
Component- Giant rat incisors
Component- A plague rat, infected blood used to pen the spell
Item- Crown of the Rat King- Allows unlimited charming of rats, speaking to rats, and even transforming into a rat (giant or otherwise). Save vs contracting were-rat lycanthropy upon donning
Component- A rat king, 13 rats with their tails tied or stuck together, but composed of wererats
Weapon-Rat Bastard Dagger- Always rolls a 1 for damage, except in sneak attacks and surprise rounds, where it always rolls a 4.
Component-Rat bones from a rat slain by a rat.
Rhino-As boar, but with bigger max +'s
Rock Baboon-I wasn't gonna do this but I have mandrills in my current campaign as the 'intelligent but primitive low HD humanoid' enemy, so. Works for cavemen too.
Potion of Devolution- Turns the imbiber into a hairy version of themselves. They may reroll all their stats with cumulative -1 penalty per prior Potion of Devolution used.
Component- Monkey tail
Spell-Clairaudience, Clairvoyance, Magic Mouth (from blasphemous apes)
Silence, Darkness (from pious apes)
This is a see no/hear no/speak no evil joke, and probably in cave-painting spellbooks
Component-Ape ears, eyes, and lips, if no spellbook-equivalent is available
Item- Decanter of Endless Dung- One round may squeeze out a baseball sized lump of putrescent dung- Those stained by thrown poop will take a -1 to reaction rolls and encounter monsters at a higher rate until they clean themselves.
Component- Colon of a constipated ape
Weapon-Monolith Club- Those struck a blow and reduced below 5HP by this petrified bone save or gain sapient intelligence permanently, as will all their descendants.
Component- Petrified ape bone
Rot Grub- I don't really like these monsters as-is, because they seem way better as ghastly parasites than just 'you tried to loot garbage and now you will die.' I'll make a post about parasite grubs.
Potion-Oil Of Rustproofing- While it won't stop magical effects or Oozes, metal treated with this will never naturally rust or corrode.
Component- Rust Monster poop
Spell- Heat Metal- Deals 1 damage +1 per round, up to a max of the armor being granted by worn metal armor and one for held weapons. Also heats metal for noncombat purposes.
Component-Alchemically treated rust monster antennae
Item- Rusted Lockpicks- You may try to pick locks twice, though the second attempt, if successful, simply disintegrates the lock
Component- Claws from a rust monster that has stolen 1,250GP worth of goods
Weapon- Sword of Rust- This sword is a crumbling ruin of rust, and though it spreads its contagion to everything it touches(each hit degrading weapons and armor by 1 point and eating through metal at the rate of 1 inch per turn) it functions poorly, as a -1 sword.
Component- A sword plunged into the heart of a rust monster that survives the ordeal.
Potion- Of Fire/Cold Immunity
Component- Salamander Saliva
Spell-Wall of Fire/Cone of Cold
Component-The spine of one salamander variety treated with the breath of its opposite
Item-Blue Flame- Behaves as fire, but burns cold and happily 'spreads' across water, freezing it. Wells up from an empty egg, equivalent to a flask of flaming oil per day. Can also be used to change fiery or icy spells or effects into instances of Blue Flame.
Component- Egg from the unnatural mingling of ice and fire salamanders
Weapon- Flame Tongue/Frost Brand- Flame Tongue may be ignited like a torch, and Frost Brand glows in below-freezing temperatures. They are always very hot or very cold respectively, and as such can quickly boil/freeze water, melt/ignite or chill/extinguish objects, etc etc. They deal the most favorable of elemental or physical damage if vulnerabilities come into play.
Component- Tongue of oldest currently living Salamander
Potion of Treachery- Acts as poisoned wine, save that whoever pours it is immune.
Component- Scorpion tail, severed in the surprise round
Spell- Water Walking
Component-Heart of a creature stung by a scorpion, but drowned before the venom could finish it off.
Item- Scorpion Shield- Grants its magical bonus as bonus to saves v poison. Defends its owner from attacks of betrayal if it is within 5' feet.
Component- A Scorpion bound in manacles and kept awake until it dies.
Weapon-Scorpion Whip- Inflicts 1 damage and a save or die poison, but on critical misses it strikes a friend, or yourself, for that is its nature.
Component-Tail of a great Scorpion fed from birth on the blood of someone slain by betrayal
Sea Serpent-BFRPG sea serpents are basically just pythons, stat and sizewise, that can inexplicably crush ships as well. I'd prefer them to be whale-sized, or even dungeon sized so you adventure inside them. Anyway, use Snake or Whale entries.
Shadow- These things seem like undead, but they're not. I think they're actually fragmentary souls, the shadow-soul, and they don't actually turn people into shadows, they liberate shadows of people to rejoin their ranks.
Potion- Oil Of Etherealness- Sinking into ones own shadow, one becomes able to slip through objects and fight things like wraiths as though they were solid
Component- A shadow, driven into a bottle
Spell- Light-ye cannot have shadow without light, after all
Component-Nothing, but the spell must be penned atop an actual shadow.
Item-Inky Ingot-As a lump of iron, but it is made of shadow and so able to affect insubstantial things.
Component- A shadow trapped on all sides by light, and so condensed to a singularity of darkness, an inky ingot
Weapon-Shadow Blade-Can strike at people's shadows to harm them. Counts as sneak attack the first time its used.
Component- One of the many uses of Inky Ingots
Potion of Blood Frenzy-Upon tasting the blood of an enemy, you fly into a berserk fury of +2 to hit and damage, but you cannot stop attacking till one of you is dead.
Component- Shark nose
Spell- Bloodscent- Follow the trail of someone whose blood you have, no matter if they fled by land, air, or sea.
Component- Blood from an animal devoured by sharks
Item- Sharkskin Leather-As magical leather. Inflicts 1 damage on melee opponents using natural weapons like fists and teeth due to the armor shredding their skin. This damage cannot reduce someone to under 1HP.
Component- Sharkskin taken from a shark that slew something with more HD than it.
Weapon- Sharktooth Club- Works fine underwater despite physics. Always floats, supporting weight up to the weight of the donor shark.
Component- Sharkteeth and driftwood
Shrieker- These border on magical items already, at least if there's smaller variants you can port around
Potion-OF SHOUTING-IF YOU DRINK IT YOU'RE REALLY LOUD FOR A FEW HOURS
Component- GROUND UP SHRIEKER
Component-A whispered word into a shrieker, blown back out once it shrieks
Item- Horn of Blasting
Component- A shrieker that shrieked for a day and a night straight.
Weapon- Whistling Mace- Careful carving allows this mace to sound as if it's saying something when swung, with a few different noises depending on how exactly you swing it. Upon creating it, you can have it tuned to a single spells' incantations, allowing you to cast that spell and attack the same round.
Component- Dried and shriveled shrieker of perfect size (if it has as much HP as you, it's of the perfect size)
Skeleton(and Zombie)-As is, these are just products of Animate Dead and shouldn't be worth anything, much like how 'goblins turned to ash from a fireball' wouldn't be worth anything.
Snake- Are dragons ascended snakes? Or are serpents the true form, and dragons a lesser corruption?
Potion- Snakebite- Drinking snake venom is harmless, though it will then collect in your teeth and allow you to make a bite attack as per the snake.
Component- Snake venom
Spell- Sticks to Snakes
Component-A perfectly straight snake
Item- Snake Rope-Rope that believes itself a snake. Can be hard to negotiate with, but quite handy.
Component- A rope that a snake mistook for another snake and tried to fight/mate/talk to before slinking off, embarrassed
Weapon- Ouroboros Chakram- A bladed ring-frisbee that can turn into a poisonous viper to bite whoever it hits, or a python to constrict them. Can only transform once per day per +
Component- A snake that devoured itself
Potion-Of Spider Climb
Component-Intact spider web
Item- Ballooning Silk-A thread of silk that allows one to float along with the wind, and acts as a parachute if one falls.
Component- Silk gifted by a parental spider
Weapon-Silk Arrows- Trail nigh-invisible silk lines that are as strong as ropes.
Component- Spinneret of a giant spider that fell to its death.