Defeat an Elder Guardian.

Spawn the Wither.

Cook and eat rabbit meat. [Bedrock Only]

Stay underwater for 2 minutes.

Dry a Sponge in a Furnace.

Push a piston with a piston, then pull the original piston with that piston. [Bedrock Only]

Breed a mule from a horse and a donkey. [Bedrock Only]

Construct a Dispenser.

Place 9 fully explored, adjacent Maps into 9 Item Frames in a 3 by 3 square.

Bounce 30 blocks upward off a Slime Block.

Poison a Witch with a Splash Potion.

Teleport over 100 meters from a single throw of an Ender Pearl.