Nocturnal enhancement

Nocturnal enhancement refers to any number of superhuman or paranormal characteristics that either manifest or are increased at night. There are several supernatural creatures that benefit from such a trait. Nocturnal enhancement is an application of lycanthropy, which is the condition in which a man turns into a werewolf when the moon is full. Vampires by their very nature are nocturnal creatures, and thus all of their abilities are at their peak during the night time hours.

For a time, Bruce Banner would transform into the Hulk only at night. This was back in the early days of his life as a monster when first had grey skin. Shortly after however, Bruce would only transform whenever he became intensely angry.

The cosmic being known as the Grandmaster gave Kyle Richmond a serum that increased his physical attributes at night. This included his reflexes, durability, stamina and strength.