The following creatures can be encountered, in both normal and "elite" versions (which convey buffs when killed).

Armadon
Biome: Forest
Description: They primarily feed on grasses and are very territorial. They are heavily armored and have lots of health.

Basking Cephaladon
Biome: Acid, Ice
Description: These alligator-looking creatures are usually found near marshy areas in the Ice biomes. They have a large amount of health.

Blitz Leopard
Biome: Forest, Acid, Ice, Desert
Description: Usually found in large flocks. Not a challenge for a Monster, however Hunters can take noticeable damage early in the encounter.

Canyon Eel
Biome: Desert
Description: Found in freshwater sources and can deal a massive damage to Hunters. They are typically rare and only appear when the "Man-Eating Eels" map effect is active.

Canyon Strider
Biome: Acid, Desert
Description: Has good agility and sense of smell. Although difficult to catch, they can be brought down with one hit.

Crowbill Sloth
Biome: Forest, Acid, Ice, Desert
Description: Featured during the tutorial, they do not have a large amount of health.

Dune Beetle
Biome: Acid, Desert
Description: Will charge Hunters as soon as they are spotted. They have a large amount of health, and do not give any buff when killed.

Glaciopod
Biome: Ice
Description: They move very slowly and only provide food to Monsters.

Mammoth Bird
Biome: Forest, Acid, Ice, Desert
Description: Found in groups that flee quickly.

Marsh Strider
Biome: Forest
Description: Good food source for Monsters.

Megamouth
Biome: Acid, Desert
Description: They remain hidden until prey walks nearby. They will then grab hold and drag them while dealing damage over time.

Nomad
Biome: Acid, Desert
Description: They react and move slowly; and have low health.

Obsidian Grub
Biome: Ice
Description: Small, heavily armored, and easy to kill.

Phantom
Biome: Forest
Description: Appear as a map effect and usually attack Hunters.

Reaver
Biome: Forest, Ice, Acid, Desert
Description: Usually will move and hunt in packs.

Spotter
Biome: Forest, Ice
Description: Very small and agile, making them difficult to catch.

Steamadon
Biome: Ice
Description: Similar to Armadon, but much smaller in size. They are heavily armored and give off poisonous steam which obscures sight and allows them to flee easily.

Trapjaw
Biome: Forest, Ice, Acid, Desert
Description: Travel in packs and are very aggressive against Hunters.

Tyrant
Biome: Forest, Ice
Description: Very dangerous creatures that are usually found near water.

Venomhound
Biome: Forest, Acid
Description: Favored attack is to leap on a lone target and poison them.