Tintin in Tibet: Part 1 - S2-E6
Other mistake: When Tintin wakes after having his nightmare, he knocks the table over along with the chess board. If you look closely, you'll see he never touches the table. (00:03:25)
Tintin in Tibet: Part 1 - S2-E6
Other mistake: When Tintin enters the cave, the footsteps follow behind him. An animation error occurs regarding one footstep, in which half of it vanishes from shot for a quick frame and then reappears as the shot starts to pan, revealing that the footsteps were not drawn by the animators in each individual frame. (00:16:05)
Answer: According to Wikipedia, he is described as being a youth anywhere from 14 - 19 years old. There is no specific age.
raywest ★