Project: Vibrant Journeys adds several ambient mobs to add flavor to the world.
These 5-legged, slow-moving creatures wander around beaches and on the ocean floor. They can be picked up and placed with a water bucket. Starfish placed from buckets do not despawn.
Flies buzz around and don't really do anything.
Fireflies spawn at night (or when it's dark). They are brightly colored and can be seen from far away.
Snails & Slugs
Occasionally found on grass.
Clams are found in most biomes in rivers and lakes, or on the ocean floor. Clams drop themselves when killed which can be cooked for food. Clams can be picked up and placed with a water bucket and will not despawn if placed this way. Clams rarely spawn with a pearl that drops when killed. Pearls can be traded to fisherman villagers for emeralds.
Frogs are found in rivers, jungles, and swamps.