[Krakenup]

When you colonize a planet, there could be a chance that plants and animals are already there. The animals could range from highly trainable animals that would give you a production bonus (possibly only if you built an animal training facility), to vicious beasts that attack and eat your population unless you build a security facility, to really tasty animals that increase happiness. The plants could also be tasty or provide an organic bonus equivalent to a free farm or be so aggressive that they prevent farming without an extension agent facility.

Just some ideas.