You were walking around the nether, and you randomly saw a mungus covered with warped mushrooms walking around, which is very strange since these mobs don't spawn in the nether...and then, a Crimson mosquito came and drank his blood, but...it started to turn blue, and started growing size, until then, it suddenly became a giant and muscular mosquito humanoid! How the hell does it happen?!

Warped Mosco: It then started to kill some other mobs nearby, it didn't noticed you...yet