The Tentacles are Eastman ZRL612R 3/8" OD x 12" EX FLEX BASIN TUBE, from Home Depot. They're a little too stiff for the best play value, but they look great! The claws -- now that he has some -- are from the Toy Biz "The Vault" Ultron figure.
The outfit with the vest is from the "Dmitri" doll from Mattel's "Anastasia" line.
The green jumpsuit in the two "Final Status" Doc Ock Pics at the top is an "Electro" jumpsuit, stripped of lightning. The belt and cuffs are yellow vynil. The boots are vision boots.