Get a Specialist-based medal that requires 3 or more rapid kills while using any Specialist Weapon.

Kill a creeper with arrows.

Discover 17 of 40 biomes.

Catch and cook a fish!

Craft and place a sign.

Craft a workbench with four blocks of wooden planks.

Relieve a Blaze of its rod.

Turn wheat into bread.

Use planks and sticks to make a hoe.

Smelt an iron ingot.

Harvest some leather.

Construct a better pickaxe.