You have to catch and breed the final evolution stage at the daycare center to obtain those. You cannot find anyone in game who will give you these eggs.
Koffing - Weezing; Stark Mount. outside in the grass.
Ledyba - Ledian; try the grass just outside the resort zone.
Spinarak - Same as Ledian
Mudkip - You have to transfer from the ruby/sapphire/emerald games.
Poochyena - Mightyena; Pokeradar in diamond version only.
Taillow - Pokeradar for swellow
Whismur - Pokeradar on mount coronet outside for Loudred
Shuppet - Catch and breed Banette on the route above the battle tower zone at night.
Wynaut - Pokeradar and breed Wobbufett at any of the lakes.