How can I get this spider to stick to an animated mesh as it deforms?

Last edit i do to the blend,

  • added planet gravity to it, so now you can walk upside down without falling of.

But you need a good entry point in order to activate it, it wont work if you try to jump on a planet for example from the bottom, you need to add a bit more code to it, but that is up to you, i provide you with an example.