Includes creatures that viciously cling to the player character, usually impairing movement and other activities while also dealing their own share of damage. Often small and work in swarms (e.g. leeches).
The first video game about Clingers was released on October 1992.
These may cause quick time events, require special maneuvres (e.g. shaking movement/view control around as if trying to shake the clingy critter off) or implicit usage of melee attacks, or something else to get them off.
A trivial example for this is a leech that sticks to the player and causes a constant health loss until removed.