Creatures include animals, humans and their mutated counterparts encountered in the Commonwealth and surrounding areas.
Most creature types have a chance to spawn as a legendary variant, as well as tiered named variants leading up to the legendary creature. A legendary creature will almost always drop a weapon or armor piece with unique modifiers (marked in the Pip-Boy inventory with a star). For more information on these modifications, see legendary weapon and legendary armor effects.
In combat, legendary creatures are very powerful, as they are stronger than their non-legendary counterpart (see below for specific differences). They are often among the highest-leveled variants the Sole Survivor will run into at their particular level. For example, at level 30 it seems more likely to encounter a legendary super mutant brute (approx. level 22) than a legendary super mutant (approx. level 10), but the lower-level encounter is still possible.
If the damage from a weapon is not high enough to kill a legendary enemy and they survive a hit with less than 50% of their health remaining, they will mutate. This causes them to regain all health. A mutated legendary enemy gains a glowing aura to show that it has mutated.
Spawn chance table
The standard base chance of a creature spawning as Legendary increases with player level (managed by the LegendaryChanceQuest):
Normal Legendary Chance %
0 - 5
6 - 20
21 - 30
31 - 40
41 - 50
The chance of a creature spawning as Legendary increases with a harder game difficulty setting. The default difficulty is always Normal.