they're fucking strange
they're also the only mammal that is poisonous.

edit: as in - the males have a poisonous spur that apparently can cause very serious pain in humans.
( but the hedgehog can never be buggered at all beards, beards, as far as the eye can see, Wed 23 Jan 2008, 23:59, archived)

late edit:
the platypus isn't the only venomous mammal, even.

en.wikipedia.org/wiki/Venomous_mammals
( but the hedgehog can never be buggered at all beards, beards, as far as the eye can see, Thu 24 Jan 2008, 0:06, archived)