Animals in your dream are the personification of both your primal self, as well as your other-gender traits (so if you're a boy it's your feminine traits and viceversa). That you are avoiding this cheetah even though it's not posing any threat to you tells me that you're avoiding and repressing a desire rooted in these primal traits. You even showed the traits to begin with - you wanted to be cool like the friends of yours...that's typically wanting to be "part of the pack" (and btw cheetahs run in packs not flocks :P). Then look, there's a pack of cheetahs that rises in your dream, too. I think this is simply your subconscious pointing a finger toward this desire you're repressing. Don't cast this kind of want aside, as the primal urge to be part of a pack/group/family.etc is actually a healthy desire and isolating can be harmful to us as individuals.