Cat Fred Evil Pet is a unique horror game where players must care for their pet cat, Fred, for four days. By providing food, water, and entertainment, players can keep Fred happy. However, if neglected, Fred transforms into an evil monster and challenges players to a scary game. The goal is to survive for four days while solving challenging puzzles and escaping the clutches of the malevolent feline.

The game features a pet shop for acquiring Fred and supplies, craft items for quests, and a narrative that unravels the mystery behind Fred's transformation. Players must navigate through puzzles and screamers to uncover the truth behind the evil lurking within their once adorable pet.