mythalogical creatures?

I was thinking that in order for any creature to be mythalogical (hope I spelled that right) all it has to do is have six limbs.

Examples... griffin (four legs two wings.) dragon (four legs two wings) centaur (four legs two arms.) fairies (two legs two wings two arms) minotaur (well never mind.)

But you kind of see where I was going with that right.

Were there ever any known creatures that had six limbs? (not counting insects.)

thanks

What about big foot and Nessy... Im pretty sure they only have 4 limbs. Either way interesting theory.