Fishes:

Fish are the source of food for larger aquatic monsters. They can be carved if speared with a harpoon.
Altaroth:

Insects that widely inhabit many areas. Noted for absorbing fruit, mushrooms and honey, then carrying them back to their nest. Materials can thus be collected from their swollen abdomens, whose colour is related to what is being carried.
Bnahabra:

Flying insects that inhabit most environments. They attack invaders with a paralyzing poison and lay eggs in carrion together with a bodily fluid that hastens decomposition. Attracted to light, they will gather around any fire.
Ludroth:

Aquatic female monsters. Ludroth form "harems" around large males, hence gathering in territories designated as breeding grounds. They are known to be extremely aggressive towards outsiders; caution is advised.
Epioth:

Submissive, water dwelling herbivores that subsist on water grasses and moss. Epioth frequently surface to sunbathe. Extremely timid, they panic when danger is near, swimming about in a haphazard fashion.
Giggi:

Wyvern larvae. Reasonably fecund, they can survive in any dark environment. Giggi are sensitive to light and heat, and so avoid torches. They are also known to leech from other animals, converting it into toxins.
Delex:

Carnivorous monsters that inhabit deserts. Delex always travel in schools of five or six. When near large monsters on a hunt, they attempt to surround the prey and scavenge food. Known to flee if other Delex are injured. Can shoot sand like Cephalos.
Rhenoplos:

Extremely territorial herbivores with poor vision but acute hearing. Rhenoplos will doggedly pursue any nearby targets they sense. They often collide into boulders, perhaps because they can't easily stop themselves once they begin running.
Urocotol:

Small leviathan monster. Like its larger form, Agunacotol, the Urocotol can swim through lava and tunnel through solid rock.
Jaggia:

Female Jaggi that stay in groups, Jaggia generally cluster around the nest to defend it and raise whelps. Smaller than mature males, but larger than and tougher than the countless young males. Jaggia also operate under an alphas orders.
Jaggi:

Highly social, carnivorous bird wyverns found in large packs. Young Jaggi males hunt in groups, attacking much larger animals. Current research suggests they operate under orders from an alpha male. Aggressive but wary of fire.
Baggi:

Highly intelligent, carnivorous Bird Wyverns that hunt in packs. Noted for their blue scales and sharp glare. Baggi are feared for their ability to release a tranquillising fluid; it can knock out even humans for several seconds.
Great Jaggi:

The Great Jaggi is the head of a Jaggi pack. At a certain age, males leave the pack to live on their own for a period of time before returning to fight for the right to be a leader. They have a very a commanding presence. It is said they can call and give complex orders to their pack with their howls and barks.
Dosubagii:

Like its juvenile pack, the Dosubagii can put hunters to sleep. It shares a similar attack style with the Great Jaggi.
Qurupeco:

Bird Wyverns with unique plumage. Well known for using their thoracic vocal organs to imitate others monsters calls, first summoning them, then using the distraction to flee. Spits a dangerous combustible body fluid.
Lagiacrus:

Known as Sea Wyverns, Lagiacrus are at the top of the aquatic food chain. Feared by sailors as 'The Lords of the Seas', they store enough electricity in their spinal organs to make the oceans surge. Occasionally seen resting on land.
Barroth:

Barroth usually remain beneath the mud, perhaps to shield themselves from heat; they are even known to fling mud to attack. They will charge in a frenzy at anything that disturbs their bogs.
Roldoros:

Alpha Male of the Ludroth. Can live on land until the sponge on its neck runs dry, at which time it retreats into the water.
Chanagable:

Chanagable is a medium to large-sized, angler fish-like monster found in the new Sunken Forest area. It sports a bio luminescent lure which is likely to use as "bait" in getting its prey's attention, particularly a curious hunter.
Uragankin:

A Barroth-like monster that has hard plates on its body. Can throw exploding rocks at the hunter. Can also roll into a ball to make itself faster.
Beliolos:

A large Pseudowyvern that dominates the Frozen Land. It attacks fast and wildly. It is also known to hover while attacking like a Kushala Daora.
Gigginox:

The Gigginox is a wyvern that lives in the caves of Monster Hunter 3's Tundra area. It is related to the Khezu, mostly in that it is a cave dwelling Wyvern that doesn't sense prey with normal eyes. The Gigginox has a special organ that can detect the body heat of its prey; this is how it can locate prey in its dark cave environment.
Agunacotol:

This new species resides in the Volcanic Region. Its body shape is relatively unique, although there are vague similarities to Lagiacrus. It is noted for its remarkable to ability to swim through lava and tunnel through solid volcanic rock. Its skin wil harden out of lava and make weapons bounce but when it touches lava, it wil soften.
Dien Moran:

A giant monster found in the desert. It fights alongside Delex. Whn fighting it, hunters wil attack it from a ship then later on land.
Navaldeus:

A giant whale-like leviathan that inhabits the oceans. When fighting it it acts like a Lao Shan Lung until the last part of the battle in which it will begin to use attacks on the hunter. It can be repelled.
Ibirujo:

A constantly hungry wyvern that attacks with its powerful jaw. A wanderer, it can be found in any region. A distressed Qurupeco can summon it during high rank quests.
Albatrion:
Image: ?
An elder dragon that controls all elements...
All info and Pics from the Monster Hunter Wiki.