Poison;
Geweon
Where's the origin? It's a good name just curious...
Also:
Stoneon
Rock type
Bug - Arthreon (arthropod)
Ghost - Phanteon (phantom)
Flying - Aereon sounds good to me
Rock - Mineon (mineral)
Ground - Terreon (terra)
Poison - Toxeon (toxic/toxin)
Steel - Ireon (iron)
Fighting - Fisteon (fist)
Dragon (?!) - Draceon (draco)
I like Draceon, that sounds pretty cool :]