charinija
Pokemon Master
Dawn didn't have Umbreon. She had Quilava
Dawn did not return with a new Pokemon. She had already caught Quilava.So far, the returning companion had a Pokémon from the region she went to (May presented Glaceon during the Wallace Cup, while Dawn returned with Umbreon after her trip to Johto), so if they keep this tradition, Iris should return with Johto with the Pokémon. The only creatures with this type in the 2nd generation region are only Ampharos (after Mega Evolution) and Kingdra
But if she is going to catch pokemon from Johto, there are 2 2nd generation dragon pokemon. Kingdra and Ampharos.
The mega evolution of Ampharos is dragon type. Not Ampharos. They can give iris the mega evolution with Mega Ampharos.