Throw diamonds at another player.

Tame an Ocelot.

Smelt Wood Trunks using Charcoal to make more Charcoal.

Swim in lava while having the Fire Resistance effect.

Cook and eat a pork chop.

Catch and cook a fish!

Befriend five wolves.

Stop starvation using Rotten Flesh.

Tame a Horse.

Dye your bed a different color.

Attack and destroy a monster.

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