I don't know if Clint drew 25000 artworks in his lifetime (that looks astonishingly huge number), but he was indeed a prodigy well known in Kerala from a very small age (3 ish if I remember correctly)
A bit superlative (philosophical bent for a 4 year old!) but this video shows some work and photographs. http://www.youtube.com/watch?v=RoOPJ1w76I8