This list is created solely based on what our 4-year old son liked watching.
Our son loves watching these short animated videos featuring a levitating-speaking mass called Dr. Binocs. The videos are all about science like human body, plants, natural phenomena and such. These are produced by Rajshri in India and the episodes are available on Youtube.
Short animated videos featuring a cackling kid explains science phenomena and how things work. These videos are available on Youtube.