Pokehunts, or (/pokehunts, /hunts) are timed 'hunts' where you must catch a specific pokemon for rewards. There are 4 difficulties, with harder ones giving access to more generous rewards.
Completing hunts will grant you hunt xp, which contributes to the monthly server pot. Earn enough contribution to become eligible for even greater rewards!
Pokehunts Main Menu
Poke Ball = Player Hunts
Master Ball = Server Hunts
End Crystal = Hunt Level & Server Pot
The varying difficulties:
Poke Ball = Easy
Great Ball = Medium
Ultra Ball = Hard
Master Ball = Insane
An example of an "easy" hunt
The server pot rewards for tier 2, if the player is eligible.