Left Monster (100% Pure Cunt):  
This slug like monster is an gender breed. The whereabouts of its origins is unknown, but these violence creatures feed and grow on different organic prey. Often entering orally or… Well as Princess Twilight can atest:  

 
They feed internally, and burst the victim in a violent manner when they come out. With each victim the grow ans gain some sort of ability they had.
 
Right Monster:  
This pony sized monster is an odd one. Often called some sort of weird mix of a pony, mosquito, and a changeling — these primarily female monsters are a playful group. Often seen near wet and moist areas outside of Equestria, their cute facade is an easy kne to fall for. In reality, these bloodsuckers have sectioned tongues is almos by itself as long as the pony and can reach 3 times its original length. They use these tongues to their advantage, for when they find prey they impale them and begin to suck them out from the inside. Once finished, they will try to eat the remaining skin and bones before taking any possessions the victim might havd carried. They are especiwlly fond to clothing and jewelry.
 
A little while after the deed is done, they will sprouts little marking on their bodies that can last from weeks to months.