skulker
/ˈskʌlkər/Definitions
1. noun
A person who lurks or hides, often to avoid detection or to spy on others.
“The police were searching for a skulker who had been stealing food from the market at night.”
2. verb
To lurk or hide, especially in order to avoid detection or to spy on others.
“The cat skulked through the shadows, watching the mouse with interest.”