holy loving stuff
just started playing vanilla and so i suck ass. after failing i got brimstone and got down to a hopeless situation in Necropolis 2 where I had one heart for the Mom fight. I had 9 lives so I just kept dying, so I fully explored the floor. On the final room I picked up a telepill that brought me to the I AM ERROR room
INSIDE THE ROOM WAS POLYPHEMUS.
I then beat Womb 1 without having beaten Mom somehow and died to Envy on Utero 2 :(