A "lindwurm" is usually in folklore the same as a dragon … It's just an older wiord. Too old, almost.
In Aventuria, however, a Lindwurm is a rather degenerated dragon. A Tatzelwurm, rather. Because wurm = worm, and a *real* dragon would apparently not liked himself to be called a "worm" …
However, even Lindwurmer and Tatzelwürmer (plural forms) can become quite big and very, very dangerous - almost like *real* dragons.
But only almost.