Minions are weak enemies that die from any amount of damage. Their feeble attacks cannot crit, ignore advantage/disadvantage, and they attack as a group, so any number of minions can be Defended against as if they were a single attack.
Minions
Core Rules v2 p. 14
Official Variants
1Overkill Damage
VariantGMG v1 p. 26
While minions lack HP, you can optionally use their die size as a measure of durability. Excess damage from an attack can carry over to other minions in range. For example, a 20 damage attack could take down two d10 minions or five d4 minions.
Related Rules
3Balancing with MinionsEncounters / Difficulty & Balance
FlunkiesMonsters / Minions & Flunkies
Suggested minion die size by party levelMonsters / Minions & Flunkies