Snaily is a light blue animatronic snail with a yellow cheerleader shirt and a red dress. Her shell is a magenta-like color, and has a logo on the back of her shirt. Snaily, since she has no arms, has sleeves with nothing in them, so they flail behind her when she moves around. When she moves, she makes a slimy slithering noise. She can hide in her shell at anytime she wants.
Snaily is incredibly hard to spot. She first spawns on the second night, and cannot be found for first night. In the first night, all you can see is her shell, which means she's hiding in her shell. She starts on the ceiling of the Show Stage, and will move to the Kitchen at a very slow pace. It's impossible to stop her, but she moves very slowly, so take advantage of her speed. If you shine light on her at all, she hides in her shell for thirty minutes (in-game). It's hard to spot her because she usually hides on the ceiling.
When she gets in the office, you have no way to stop her at all. After she enters the office, she kills you instantly by appearing from the ceiling and dropping on you. You can't stop her from killing you when she reaches the office because it's easy to stop her from entering your office overall.