Stay underwater for 2 minutes.

Craft and place a Sign.

Power a Furnace with Lava.

Swim in lava while having the Fire Resistance effect.

Create an Iron Golem.

Construct an Enchantment Table.

Destroy a Ghast with a fireball.

Breed two cows with wheat.

Tame a Horse.

Catch and cook a fish!

Use Shears to obtain wool from a Sheep.

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

Wear a full suit of Iron Armour.