They lack any special ability, and are easily the weakest creature in the game. They are only good at one thing: dying. Because of their low Attack skill and damage, any stack of peasants will most likely do less damage than the number of creatures in it. Their Damage is constant, therefore spells like Bless and Curse will have no effect on peasants.
Peasants may only be reasonable when their hero has high Attack and Defense stats adding to theirs, but even so their Health, Damage and Speed are too low. Their low price of 20 gold is not a big gain because one goblin (which costs 40 gold) can kill 4 or 5 peasants. Because of the limited number of slots in a hero's army, the peasants are almost sure to be left out of final armies. Early on, peasants are best used to defend ranged troops. Later on, they are better off left in towns. Generally, the best way to gain peasants is from joining wandering armies or dwellings as free troops for early game, as you are not wasting any resources on those troops.
|Heroes of Might and Magic I creatures|
|Farm (Knight) units||Peasant - Archer - Pikeman - Swordsman - Cavalry - Paladin|
|Plains (Barbarian) units||Goblin - Orc - Wolf - Ogre - Troll - Cyclops|
|Forest (Sorceress) units||Sprite - Dwarf - Elf - Druid - Unicorn - Phoenix|
|Mountain (Warlock) units||Centaur - Gargoyle - Griffin - Minotaur - Hydra - Dragon|
|Neutral creatures||Rogue - Nomad - Ghost - Genie|