Hi! I'm looking for an old cartoon that aired ages ago (or not quite, i remember the animation was pretty good)?

I watched it when i was like 6 years old so i don't remember any part of the title at all but i do remember it was about a boy and his grandfather traveling through the world in a locomotive. Also, there was this dragon that was tracking them down. As silly as this sounds (even for a cartoon meant for 6yo) she (the dragon) wanted them to teach her how to laugh (cause apparently she could only cry even if she felt happy).

That's all i can remember about this cartoon in general, but i do remember one episode slightly better: it was about this man that lived in the desert all alone because a mirage made him appear (from the distance) like a giant and so everybody was scared of him.

That's everything; good luck with that (i know i didn't have any)