In the alternate realm of Burr, Pterandons (also called Pteri) were biologically created both to harass the dragons of enemy Mages in battle (since they are quicker on the wing) and as messengers (because they can endure flying long journeys). They are highly intelligent, but shrewd and they are incredibly loyal to their Mages. They are fond of ribald jokes.
They are deadly, especially to dragons. Their sharp beaks aren't hindered by tough dragon scales. They keep pecking until they find a weak spot in the dragon's armor. They fight in flocks. A dragon who has to deal with three or four Pteri is in grave danger, but they can usually hold their own against just one. Dragons will outright murder any lone Pteri they happen to encounter.
Pteri maintain an uneasy truce with dragons and the other prehistoric beasts created by the same Mage that created them.