Tintin in Tibet: Part 2 - S2-E7
Revealing mistake: After the "previously" clip, Tintin, Haddock, Snowy and Tharkey continue their walk. In the second shot, the four walk over a hill. The first footstep on the edge of the hill is incorrectly drawn and looks unrealistic. (00:24:45)
Answer: According to Wikipedia, he is described as being a youth anywhere from 14 - 19 years old. There is no specific age.
raywest ★