it will turn into something pretty but cant remember what it is. depends if you want the lily buds to survive. You can always move the caterpillar to another plant.

Thanks seaburn, I just wanted to make sure that i'm not letting something harmful eat my plants thinking that it is a caterpillar. Dont really mind sacrificing a few flowers. :)

It looks like the larva of a sphinx moth of some species. Dont know which one though. Large, elegant, sometimes colorful "stealth fighter" moths. They are important pollinators, especially of scented plants, such as Nicotiana or Datura. On the other hand, their larvae can defoliate their host plants!

Thanks tugbrethil, it is still going on eating my plants. Hope to see its more beautiful form soon!

Fair warning, if it is a sphinx moth larva, it will get pretty huge, and eat a lot of foliage before it changes! The infamous tomato hornworm is its kin.

Thanks Tug, I'm going to make sure it doesn't get anywhere near my favourite plants. Lilies are ok, I've got too many of them.