American Dragon Meets Gargoyles:
1. The Hunts Clan and the Pack team up to take down the Gargoyles. When word gets to Jake, he and the other gargoyles that remained uncaptured (or Eliza Maza if you prefer) track them down and prepare for a final confrontation.
2. (Continuation or separate story) Demona and the Dark Dragon team up and Demona breaks in Jake's grandpa's shop for a magical item to use for her vendetta against the humans. Jake tries to track down who was responsible, coming across Goliath and company. After a fight via misunderstanding, both sides realize who was really responsible and they try to stop their foes before it's too late.
Both are shows under the Disney name and take place in NYC (why's it always New York City?). I do believe if written right, it would make a good story.