Creature

A creature is any living or animate being that can act in the game world. This includes:

Characters (player characters and NPCs)
Monsters (any stat-blocked enemy or entity)
Animals and Beasts
Constructs, Undead, Celestials, etc.

Objects and environmental hazards are not creatures.
Creatures can be affected by spells, abilities, and effects that specify “a creature.”

Senses

Senses

Blindsight

A creature with blindsight can perceive its surroundings without relying on sight, within a specific radius.

Creatures without eyes, such as grimlocks and gray oozes, typically have this special sense, as do creatures with echolocation or heightened senses, such as bats and true dragons.

If a creature is naturally blind, it has a parenthetical note to this effect, indicating that the radius of its blindsight defines the maximum range of its perception.

Darkvision

A creature with darkvision can see in the dark within a specific radius. The creature can see in dim light within the radius as if it were bright light, and in darkness as if it were dim light. The creature can’t discern color in darkness, only shades of gray. Many creatures that live underground have this special sense.

Tremorsense

A creature with tremorsense can detect and pinpoint the origin of vibrations within a specific radius, provided that the creature and the source of the vibrations are in contact with the same ground or substance. Tremorsense can’t be used to detect flying or incorporeal creatures. Many burrowing creatures, such as ankhegs and umber hulks, have this special sense.

Truesight

A creature with truesight can, out to a specific range, see in normal and magical darkness, see invisible creatures and objects, automatically detect visual illusions and succeed on saving throws against them, and perceive the original form of a shapechanger or a creature that is transformed by magic. Furthermore, the creature can see into the Ethereal Plane within the same range.