Hoothoot is the Pokémon in Pokémon Pokopia described as enjoying darkness.
Pokopia links Pokémon appearances to habitat conditions. Players must create environments that suit particular species, rather than expecting every Pokémon to appear in the same type of location.
The game article gives Hoothoot as a clear example of this system: darkness is part of what the Pokémon prefers. This makes time of day and environmental design relevant to attracting residents.
Hoothoot is a sensible example because it is associated with nighttime in the wider Pokémon series, but the specific trivia fact concerns Pokopia’s habitat needs. Noctowl, Murkrow, and Sableye may also suggest darkness, yet the named example in the game’s description is Hoothoot.