Goofs

A Goof is typical tern describes the animation errors/bugs that has been made in the animations by mistakes while under development. Goofs are common, mostly in cartoon shows, and Happy Tree Friends is one of them that include lot of goofs. These are typical mistakes that development didn't realized to check the episode carefully before releasing the videos. While they don't affect the episode much. Sometimes it can create theories and speculations. Depends on how much the creator careful is, there may be a lot or very few goods in an episodes.

Goofs are not limited to animation error however. They can also be as a text error, example: Voice actor for certain character is not listed on the crediet/ending of the episode.