Tasks

Those tasks can be received from NPC Grizzly Adams, which can be found in every city.
Example how to take task Hi->Tasks->Medium->Vampires->Yes
Example how to cancel task hi->cancel->yes
The reward can be checked in the table below:

Easy

Task Name	Monsters	Kills	Level	Reward
Weak Minotaurs	Minotaur	500	30	dragon shield, 30 minotaur leathers
Weak Orcs	Orc Spearman, Orc, Orc Warrior	500	30	warrior helmet, ring of healing
Weak Dwarfs	Dwarf, Dwarf Soldier	500	30	spirit cloak, 30 iron ores

Medium

Task Name	Monsters	Kills	Level	Reward
Strong Minotaurs	Minotaur Archer, Minotaur Guard, Minotaur Mage	500	50	nose ring
Barbarians	Barbarian Bloodwalker, Barbarian Brutetamer, Barbarian Headsplitter, Barbarian Skullhunter	600	50	spellbook of mind control, 20x sudden death rune, energy ring
Demon Skeletons	Demon Skeleton	400	50	demon shield, 10 demon dust, stealth ring
Vampires	Vampire	300	50	vampire shield, 10 vampire dust, stone skin amulet
Necromancers	Necromancer	300	50	boots of haste, 40 blue piece of cloth, 100 power bolt

Hard

Task Name	Monsters	Kills	Level	Reward
Quaras	Quara Constrictor, Quara Hydromancer, Quara Mantassin, Quara Pincher, Quara Predator	400	70	skull helmet, 50 small sapphire, 30 fish fin
Hydras	Hydra	800	70	swamplair scales, ring of healing, 40x ultimate healing rune
Frost Dragons	Frost Dragon	800	70	angel bow, 300 sniper arrows

Very Hard

Task Name	Monsters	Kills	Level	Reward
Demons	Demon	500	100	helmet of demonic fire, angelic ring, 80 small diamonds
Grim Reapers	Grim Reaper	600	100	boots of great haste, time ring, 90 small amethysts
Juggernauts	Juggernaut	1000	100	golden boots, golden legs, 20 gold ingots
Powerful Undeads	Betrayed Wraith, Lost Soul, Blightwalker, Dark Torturer, Undead Dragon, Hand Of Cursed Fate	1000	100	magic ice armor, 90x avalanche rune, amulet of loss
Castle Guardians	Crusader, Royal Halberdier, Champion	2000	100	demon legs, 200 infernal bolt