This is Makadee, a creepy creature originated from the mutation of a suffering soul who arrived the Realm of Sin, ruled by Herr Sünde, in the depths of the Nether. This soul belonged to a murderer and, due to its sinfulness, the lords of punishment transformed him into a horrible, bloodthirsty monster.
It is said that Makadee wanders the oceans of lava of the Nether, looking forward to eating your tasty flesh after taking you to its spiderweb cottage.