using entitydata @e {id:"zombie"} doesn't update the entity

The End is generated in slices in the Debug Worldgen mode

Flying into an gold plate in debug mode will crash minecraft

Retracting piston deletes ANY block in the place the head should be.

Redstone pulse after resetting the over-extracted comperator

Breaking piston arm in creative

(Sticky) upward extended piston gets power from the redstone block it is pushing.