Invisible

An invisible creature is impossible to see without the aid of magic.

Their location can be detected by any noise they make or any tracks they leave.

An Attack made by an invisible creature against creatures that cannot see them has Advantage.

A Melee Attack made against the invisible creature has Disadvantage.

Ranged Attacks require sight and thus cannot be made against an invisible creature.

Most Spells require sight and thus cannot target something Invisible.