Let me explain.
In some episodes, in the background you'll notice odd creatures or a pair of eyes looking under the bushes. This is true, next time you watch Sanjay and Craig, just look very carefully in the background, you'll see it.
This explains a very strange theory, and all of the characters are dead, the show is just the past of the friends, the whole theory is down below.
Sanjay has mental problems in the show, which is why he's always so hyper and jumpy. His imagination makes him think that his pet snake talks. Sanjay was killed in a car crash, his mother was supposed to be driving him from "Tufflips Camp". When the car crashed, it crashed into a concrete wall, giving Sanjay a severe whiplash. Darlene survived, but she had serious brain injuries, and had mental problems, leading to hell.
Craig was Sanjay's pet until Sanjay was possessed by a demon, which left him alone. Sanjay's parents put Craig up for sale, since they didn't need Craig anymore. The following night Craig escaped the house and slithered around the back yard. A bat fluttering with Sanjay outside saw him and bit him, killing Craig with rabies.
Megan was insane for pagents. Selfishness and greedyness took over her. Once at a pagent, she got expelled, causing Megan to freakout and go insanly mad. She was seething with rage, and all it took was one pagent. She destroyed her room and forced her mother to give her a trophy. Megan started to ruin her bed, also. She started jumping on it, but jumped to high and hit the ceiling fan, and was decapitated or eyes ripped off of her sockets.
Hector was made fun of all the time at class. For his eyepatch and his funny voice. People called him "that loser" or "fat pig". Hector got angry at this, but he knew that there was nothing he could do. It got worse over the years, and Hector became pushed around, until his father beat him to death because he was not giving %100 in school or deheaded by Sanjay. _____________________________________________________________________________________
This is what lies behind "Sanjay and Craig" and it's sad, but it's the truth. They're all dead from different accidents, and went the place that dead souls go, another world. Souls go there when their body dies, and Sanjay, Craig, Megan and Hector went there.
The whole series depicts that place, and in that place they are always being watched by gaurdians so they don't escape and try to live in another soul. This explains the weird creatures in the background, watching Sanjay and Craig while they do things with their dead friends.