You've got club feet, literally. Both your feet shift and look like they're made of wood. You can pull them off and they change in shape again; hardening and becoming nice and straight. You can use them as a d6 wooden club, but you cannot walk on that leg until you put it back.
 Both of your legs turn into long, trailing centipede bodies. They can act independently, but are connected to you and one along cannot support your weight beyond a very slow, stilted crawl. However, using these legs, you can crawl over rough terrain at your normal running speed without penalty, and even climb up shallow inclines too steep for a normal being to climb. You also gain +1 AC on your lower body, but cannot wear pants or leg/foot armor.
 Your legs and lower body disappear and turn into a genie cloud, with an elemental twist. Roll a 1d4 to determine the element.
- Fire- Cloud is hot steam with sparks
- Ice- Cloud is a blizzard with snowflakes
- Lightning- Cloud is a crackling thundercloud; static-shocks on touch
- Earth- Cloud is a duststorm with little pebbles flying around in it
Each cloud grants you resistance to that elements. You take -2 damage from all spells or attacks of that element. The exception is Earth; which instead grants +2 to saves versus paralysis and lets you poof above ground if you're ever buried alive or entombed in stone.
 Your legs twist and turn into a giant metal spring. You can't take steps, you have to bounce around. You can make incredible 30 ft jumps, and hazards like caltrops and bear-traps don't harm you at all. You cannot wear lower body armor or kick, sidestep, or take careful steps. You get -4 when trying to sneak, and -2 to saves versus getting tripped or shoved.
 One of your legs is randomly selected. This leg, below the knee, permanently changes form into a rail-thin impish demon, which folds its arms around itself and stands up straight, letting you use it as a leg. If you kick someone with it, the target must make a save or be put under a minor demonic curse, like smelling of brimstone or coming down with a minor disease. The imp frees itself from your leg when you sleep or rest, but claims to be bound to you and will always reappear to connect itself to your stumpy knee. It doesn't ask for anything, but tries to tempt you into minor sins and lying to your priest. You become crippled on holy ground, since the demon cannot enter, and if a turn undead roll against you is successful, you'll lost your imp-leg.
 Both your legs become blades; below the knee, you have curved katana blades for feet. Doesn't cause you much issue moving around, and you can perform acrobatic kick attacks dealing 1d6+1 damage like a true ninja assassin.
 Your legs transform into cricket legs. You can't wear armor down there and you get -4 to sneak; your steps chirp. But you can leap 30 ft and get +1 AC from the insect chitin. You can also kick as an improvised weapon, dealing 1d4 from the intense strength of your kick and the barbs.
 Your legs and lower body transform into a semi-solid flowing clay. The clay is usually in a boxy shape, which can be rounded at the corners to allow you to roll it as a form of movement. Legs are too complex for it to manage, but you can shift this clay into many forms; large ball and chain that let you sink in water quickly, a tower complete with fake window to let you get a few feet of height to look around, sinking halfway to the floor and having your legs peel around your body in the form of a large pot; granting +2 AC as long as you don't move, and so on. Separating this clay from your body is as difficult, and deals as much damage as, normal injury to your actual legs would be.
 Roll for a Random type of Livestock (or 1d6 on the Random Animal Table). Your lower body turns into a 4 legged body of that animal, with your upper body poking out where the head of the animal would roughly be- exactly as a centaur. You gain the ability to eat foods that that animal can and gain +2 hit points from bulk, but now have trouble fitting into tight places and need special armor and shoes to fit you. Stable boys can be hired to keep them cleaned and pedicured.
 Your legs and lower body transforms into a single large metal wheel. It can spin and moves much faster then a regular running human on a road or smooth stone surface, but has trouble navigating bumpy surfaces and is useless when swimming. If you're at least 6th level, your character can figure out a method to use the wheel as an underwater propeller, giving you extremely fast swimming speed and letting you leap from water high into the air, such as onto the decks of ships from below the waves.
 One leg at random becomes mechanical. The mechanical leg works exactly as a regular leg works, and is made of metal. It is very durable, and is made of alloys to resist corrosion and magic as well as a +1 magic sword/armor-piece can. The leg has no special properties beyond toughness; as long as you have it you take ½ damage from caltrops and burning embers, have a 50% chance to avoid bear traps, etc.
If word gets around that you have this advanced leg, thieves and assassins may be hired to retrieve it from you one way or another. Wealthy nobles with old war wounds or crippled sons would be very happy to have such a one-of-a-kind prosthetic, which would leave you lame or dead.
 Your feet turn backwards. You get -1 to climbing and stealth rolls with your floppy, awkward feet, but you leave backwards footprints and are very hard to track for that reason.
 Kick of the Heavens. One of your feet at random becomes swollen and crackles with purple energy, sizzling and burning uncomfortably whenever submerged in water. If you kick with this foot with all your might, it explodes in a blast of electrical energy that deals 2d6+2 shock damage and knocks the target back 1d4x10 ft. After this has been used this foot is gone.
 Both your legs shrink into small, warty green legs. This significantly shrinks your height and makes you much slower, plus you can only wear small size armor on your lower body. However, these legs regenerate over 1d4 days if they are severed or broken.
 Your bottom and top half can separate at will. Both your legs and groin will pop off your body whenever you will it, and have an almost human level of intelligence when separate. They can detect speech by standing still on the ground and sensing the vibrations of a voice, but cannot read. The legs you have can run errands for you, separate off your body to avoid an attack, kick people while your top half is unconscious, etc. Your bottom half gets ½ of your HD and class features while separate from you, except spell casting which requires your top half only.
If the bottom half of you dies, you must roll a save vs death. You lose ½ your HD permanently if you make the save, or die if you fail.
If the top half of you dies, your legs become forlorn and wander, still alive but without a mind or face. They will probably get a new job as the messenger of a ninja clan, running across still water with great speed, or wear armor and kick goblins to death for gold.
 Your legs become ridiculously bloated. Huge, with grayish flaky skin. It's uncomfortable to wear pants and you look ridiculous, but you gain +2 hit points and can now trample small creatures like goblins as though you were much bigger then you really are.
 Starting at the knees and going down, both of your legs start to shrivel up, become scaly, grow talons where your toes where, and have a feathery fetlock decorating your shins. The feathers here can be plucked and thrown to work as 1d3 improvised weapons, or can be flung with an expertly timed kick if you're at least 3rd level in a fighting class or have +3 Dexterity.
 Large orange tubers start to grow from both your legs. These tubers are extremely flammable when attached to your body, guiding flame up your legs through your clothing and onto your waist and crotch; all fire spells and attacks deal 1 more damage to you if you don't clip these tubers every day. Once detached from your body and dried, the tubers become extremely flame resistant instead. The clippings of one season's worth of growth can be used to create a cloak of fire resistance, some heat resistant gloves, etc.
 The skin from one of your legs at random sloughs off. The muscles behind a thin bit of shin and thigh bone and skin become exposed, and turn into lumpy hard pulsating things. They will fall out of your leg if not constantly bound with fresh bandages or wrappings. The muscles are still quite strong as they would be with your legs as normal, but can be removed for individual healing and cleaning, or accidentally lost to lose permanent strength in that leg. If you remove enough of these muscle-lumps from your legs that walking becomes difficult, you could place them inside an enclosed space like a box or chest to crush and squeeze things inside, similar to a muscle in nature; breaking aside small bits of shell or bone.
 Every three days, your legs begin to transfer their life force between themselves. Your left leg will darken, shrivel, and become black and almost useless with a limp, where as your right one will become strong, muscular, and can grant you additional jump height and kicking damage. This process stops and reverses every three days- at the middle of the process both legs will be mostly neutral. If you drink copious amounts of healing potions or have powerful healing or protective spells, it may be possible to keep the empowered leg while also making the shriveled leg healthy as it normally would be without the mutation.