Complex sentence: These enhanced fire-lizards were originally referred to as dragonets because of their likeness to the dragons featured in old myths from Earth; however, their ability to breathe fire led to the eventual use of the name fire-lizard.
Split into simpler sentences: These enhanced fire-lizards were originally referred to as dragonets because of their likeness to the dragons featured in old myths from Earth. However, their ability to breathe fire led to the eventual use of the name fire-lizard.