UPDATE: This has been disabled now. It was fun times.
Want to dress up for Halloween? Hold a block in your hand and type “/hat” to put it on your head! It should work for any solid block (and more). For even more fun, try dressing up as a scary monster or cute animal! Use “/costume [mobname]” and everyone ELSE will see you as that mob. Type “/costume” again to go back to human form. Type “/costume types” to see all the mobs you can dress up as. Have fun!