Zombie picking up items

I have evidence of Zombies portraying Endermen-like behavior; that is,Zombies being able to pick up and hold world-blocks in their hand. This does NOT, however, affect the gui or configuration of the Zombie, because the Zombie can still sense and attack a player normally. This came out of nowhere, I wasn't "bug hunting" as some might call it. It doesn't really affect the game, and this is the first time I have seen it. I jsut think it might be details to be fixed. Thanks for listening!