Homebrew Alien slime Species Details

 Created in an factory, from an world that was long destroyed, this specie was an created as pet, that transforms into what it eats, and used to battle other pets or wild creatures, it can't change its mass, without leveling up. 

it'll scale it's density and size aproperitly, since if it has an mass of 100 pounds, but if it transforms to an ant, and scales it to the size of an small dog, it will still have high density, but also being way bigger then what it originally transformed from, being way stronger, but if it keeps scaling bigger into the size of an elephant, with the same 100 pounds of mass, it'll have very low density and won't be able to take an hit, compared to if it was the size of an small dog with 100 pounds of mass.

It'll eat any species except its creator specie, thankfully they are dead long ago, its poor in combat in its slime state, with no fighting instincts, other then trying to absorb, it's still intelligent, but it has to absorb an creature to be able to fight efficiently, and the body has to be alive,  in one piece, but not struggling enough to escape or fight back(asleep, paralyzed, ect is preferred).

It doesn't gain mass from eating, only from leveling up, and every 5 levels after level 5 you can add an additional creature to make an functional chimera,(ex: at lv 5 you create an alligator with bear limbs, at lv 10 you add an snakes poison gland to the alligator bear.)

 it doesn't save previous forms, so if you absorb an new creature,  then transform into that creature,  without being level 5, or not wanting to incorporate that creature,  then you transform into the newest creature you absorbed, but if you want to transform into an previous form, you have to reabsorb one of that species.

but if you are using the additional chimera slots, when you transform into the new creature you don't have to reabsorb the creature you didn't replace. (ex: you have an deer,dragon hybrid,  but you want to change out the deer part, you can, without dragon part being reset)

it doesn't change colors, even when transformed (ex: so if the slimes color is red with white ring spots, and if it transforms into an human, then it will have human skin texture but with red skin color with white ring spots from the slime, or if the slime is white, with an single black mark and transforms into an ant, then the ants shell will also be white, with an black colored mark, the slime can be any color or pattern)

The class and stat distribution remains the same, when transformed, mass is hp in slime form, but when transformed, mass is added to the additional hp from lv ups at an reduced rate. The combat stats in slime form is greatly reduced 

It doesn't need to eat food, but it won't transform from eating while transformed, it has to detransform, to absorb the new creature in slime form, to transform. 

At lv 1 they have around 100 pounds of mass and each lv up they gain mass exponentially up to 1000 pounds at lv 20, which can be compressed to add density.

They don't grow old, can't split/clone itself and can't reproduce their own species.  

 

Ps I don't play dnd and I don't know how the dnd system work, so you don't have to stick with the numbers, or things I put, and I don't think this race is OP, but if it is, then don't do the exponentially increasing mass, from lv ups, or lower max mass to 200lbs at lv 20, because you still have the stats and classes. I recommend absorbing small insects first, since they can't escape and are weaker, but when you scale them up, they become powerful, and I don't recommend absorbing thing that have more mass then you without them being unable to move, which is extremely hard since they need to be alive with only minor wounds to no wounds, to be able to absorb them, and absorbing them takes quite an while, you have to transform back into slime form to absorb them, but your stats are reduced in slime form, so they need to be weak, I would recommend targeting the weaker ones in an species like the children or elderly first, then targeting the able bodied ones, ps the lv of the one being absorbed doesn't matter, but if you use an child and scale it up to adult size, then the proportion would be not ideal, and since age dimorphism make the child and elderly stages weaker then the prime adult stage. Anyways, the level and class of the absorbed doesn't matter, only it's physically fit. You can't read their memories,  but you do gain their racial trait, like night vision, and back to insects you can get them and scale up to big sizes with them suffocating because of the slime doesn't replicate part where it's not needed, like the lungs and stomach, since the slime doesn't need air or food, it still copies the muscles, but in stead of blood it uses altered slime, as an super fluid.

Alien slime Traits

Transforms into creature it absorbs, control size, control density, can't gain mass without leveling up, doesn't need to breathe, sleep, or eat for sustenance. Able to chimera at higher lvs, self recovery in slime form