Theory:The Watcher

+ When Teddy made a cart disappear (Tabula Rasa), he did it in front of the ball toss game. The Watcher is the ball toss attendant.
+ Teddy's ability allows him to hide things. The Watcher mysteriously pops out of nowhere, perhaps being able to make himself disappear.
- Teddy's ability appears similar to dimensional storage. That wouldn't explain how he could appear and disappear in literally the blink of an eye.

+ In chapter 7 of Slow Burn, the Watcher made Jennie Bowman inaudible and invisible. This seems like a possible application of cloaking.

- Similar effects, different abilities.

- They have different abilities.

+ Teddy could have manipulated Sylar's eyes to make it seem as though the cart disappeared.

- Samuel would know if this wasn't Teddy's ability.

+ Teddy could have manipulated everyone into believing this was his ability.

+ Nothing suggests that Samuel does not know what Teddy's ability is.

- The Watcher claims that every wept when they discovered he was gone but gradually accepted it. The carnies still know Teddy is around.

+ He never stated who wept for him. It could have been his family, at a time before he joined the carnival.