The Retro Wooden sword:

Makes every second melee attack shoot out a fire ball directly infront of the player.

The ring of the Melur:

Transforms the player into a merfolk on land and their original race in water.

-25% Speed +25% Damage

The Scarab of the desert:

While in desert biomes, the player transforms into a mummy, and has permanent thorns which deal 30 damage.

-50% Speed +10 defense

The random flask:

When drinking a potion, the player gains random positive effects (75%) or random negative effects (25%)

All trinkets are rare(1 out of 20) drops from the corresponding mobs, vultures for the scarab, sharks for the ring and skeletons for the sword and the flask.