[quote=@TentacleLord]
[@Experiment 249]

Point of note, I'm not certain if wyverns can breath fire, although I'm pretty sure they can't. Could be wrong though.
[/quote]

In the second Fire Emblem, Mystery of the Emblem (which was translated on DS but is very rare) Wyverns had two legs, and [i]could [/i]breath fire. They looked like this:
[img]http://vignette2.wikia.nocookie.net/fireemblem/images/b/bf/Dragonknightmount.jpg/revision/latest/scale-to-width/250?cb=20130124025346[/img]

As far as I'm aware they have appeared in this form in other Fire Emblem games but not any of the ones translated to english. In the newer ones the Wyvern's have been mostly replaced by four legged more draconian creatures that never display fire breathing abilities.