Transylvania is inhabited by humans, vampires, and werewolves. You cannot tell simply by looking at someone what he or she is. However, humans always tell the truth, vampires always lie, and werewolves sometimes tell the truth and sometimes lie.
In addition, some inhabitants are quite insane and think all true statements are false and all false statements are true. The other inhabitants are sane and correctly distinguish between true and false statements.
So, in Transylvania a false statement could be made out of malice or simply out of honest delusion. For example, a sane human knows the earth is (approximately) round and says so, while an insane vampire believes the earth is not round so will lie and say that the earth is round.
Suppose a Transylvanian named Lucy claims to be human. What do you know about Lucy?