1) Foolishly selfish person 2) Hinderer of a sort 3) Monopolist of a sort 4) Needlessly selfish person 5) Road hog 6) Selfish one 7) Unreasonable hoarder 
[n] - someone who prevents you from enjoying something that they themselves have no need for
noun someone who prevents you from enjoying something that they themselves have no need for
a person who selfishly keeps something that he or she does not really need or want so that others may not use or enjoy it.