Firelizards
Firelizards exist in our world and it is relatively common to have one, among weyrfolk or those living in warm or tropical climates. A larger egg likely to contain a bronze or gold may run as much as what a typical person would earn in 2-3 months of work, but the smaller greens and blues are easier to obtain, despite the low survival rate of green clutches.
The golds and bronzes are the most reliable about taking messages and such, but all colors can be used for this or other small tasks that one could train, for instance, a monkey to do.
There is currently no firelizard code on the game; they're just roleplayed as any other pet or possession. We ask that players speak with their area staff before running a firelizard hatching.