Homebrew:Minion

Minions are a rule in 4e D&D. In 4e, a minion is a normal enemy except that it has 1 hit point, and does not take damage on a miss. This allows the DM to include many more enemies in a combat, without increasing the deadliness by as much as it seems. It also lets players feel much more powerful, as they kill masses of enemies.

For 5e D&D, the conversion is simple: change the monster to have only 1 hit point, and it takes no damage when it succeeds on a save. Any monster can be turned into a minion, although it doesn't necessarily make sense for all monsters. Nobody would expect Aspect of Tiamat to die to a single hit, for example.