The silkworm is one of the world's most genetically modified animals. Silkworms were first domesticated in China over 5000 years ago. Since then, the silk production capacity of the species has increased nearly tenfold. Silkworm is one of the few organisms wherein the principles of genetics and breeding were applied to harvest maximum output. It is next only to maize in exploiting the principles of heterosis and cross breeding.
--Wikipedia on a non-vegetarian, GMO fabric