After being pushed (with water) from a drop of at least two (2) blocks, the mob will appear to be halfway inside of the block below. The mob's hit-box (where they can be injured/hit) will stay in the spot where it would be if the mob were not underground. The mob will appear to move normally in the ground. After moving for a while or attempting to jump, the mob will "teleport" up to the normal position and act normally. Screenshot attached.