i just recently noticed something on the opening credits to the episode mortos der soul stealer

the part when the pipe thingys are coming up
keep looking at the middle one, if you pause it frame by frame, right when it's almost close up to the screen, you'll see on the left side of the pipe, you'll se the bloody gir
it's a litle bit faded, so look carefully

the faded bloody gir is also in a few other episodes, but this is the only one i'v found
follow this link to know more --> link

WARNING!!!!
DON'T TRY THIS IF YOUR THE EASILLY SCARED TYPE!!!