You can't but you can make one @ dragon quest monsters.com
in the cave northeast of bloomingdale. keep going down the levels until you get to the bottom. she will be their with a giant spider.
gittinghampalace
oaklore dragon defend oaklore quest
nythrea's first quest you'll find it on that one
U have to fight him in warlic's quest(dragon egg)
In Dragonfable you can find the mummy dragon in a quest called Dynasty Tomb in the Sandsea from Zhoom.
Go to below link and go to non-member quest and find dragon slayer quest. It is a good guide with screenshots.
You find them in high level 'volcano' grottoes.
you can get it from certain monsters
ask 4 a quest! OR invite her!
You can find them at the Realm of the Mighty.