thats an INFERNAL mob underground, trust me, as an alpha tester, that has killed me MANY times, and one of those has actually placed cobwebs all around the private beta for server's spawn
Its always fun to be walking around scavenging and then boom your thrown up into the air by a mob you cant see! Or webbed out of nowhere. good times. Infernal mobs....make the game a challenge
Hehe, walk around and Boom....50 blocks in the air and splat. I try to aim for any water if I can. Or un in the leaves. Leaves seem to slow them so that you do not go too high. Keep your F3 on, write where you died, if you are lucky you will /rt close and save a few things although it is best to go ahead and make new ones. lol,