I have a breeding chain that crosses through (almost) every egg group atleast once. It started with 2 Weezing and 2 Muk. Most recently, its back in the Inditerminate Egg group with a SHINY Koffing (male, nicknamed Zyenith) and a Gardevoir currently breeding. The chain fills 2 and a half boxes, most of them fully evolved. The Shiny Koffing is LV 63, Holding an Everstone, Max out "Cute" contest stat and all cute ribbons. Its not much of a battler, but its good in contests.