Throw diamonds at another player.

Trade for the best possible price.

Cook and eat a pork chop.

Build some bookshelves to improve your enchantment table.

Kill the Enderdragon.

Enter an End Portal.

Relieve a Blaze of its rod.

Acquire diamonds with your iron tools.

Construct a Nether Portal.

Construct one type of each tool (one pickaxe, one spade, one axe and one hoe).

Use a saddle to ride a pig, then have the pig get hurt from fall damage while riding it.

Attack and destroy a monster.

Use planks and sticks to make a sword.