Blending in with one's surroundings is a common strategy for predators to use in capturing some other animal to eat. Leopards are good at it. So are spiders, anglerfish, and octopuses. Simon's Cat tries it out.
But Simon's cat is neither a spider nor an anglerfish, although he probably thinks he's a leopard. He just doesn't quite have the needed skills. It might have been his comfy suburban upbringing, or it may be just his bad luck.