The ones Touched by the End.

if a you open the ender portal within a matter of time a mob will fall threw, changing it to be "Entity_Name Touched by the end" after 3 days of corse. it will enter what looks like the mobs spawn egg with an ender mans egg covering 1/3 after the 1st day, 2/3 after the 2nd, and so forth. as the sun sets on the third day, when the sun sets, you will be unable to sleep that night, on attempt to enter the bed, the text "The End Is Near" will appear on the screen when the sun has set completely, the end touched mob will appear, the mob will have black and purple hilights and glowing purple eyes the mobs health bar will be on top of the screen. the mob will have 3 times its health and strength, with the ability to teleport. now it could just be a pig or something, or it could be a warden idk, you can't be too carful. any thing from the end will be unaffected and any thing from the nether will be dead. you will have a chance to destroy it if you get to the egg and destroy it. of corse, this whole event could be avoided by blocking of the entrance and making sure nothing can spawn in there.