The term describes something that is exceptional, or awesome. It is derived from "pwn" which is ultimate nerd internet ownage. To own ponies is to do something amazing or be amazing.
The reverse of this, sucking, is to "blow ponies".
"She let me get to third base on the first date! Third base totally owns ponies!"
1)If something owns heads it is supposedly really good, sublimeeven.
2) ...delivers the Murkle Circle
3) beats/owns people
4) ...opens a can of whoop-ass on your head
Eating an apple everyday owns heads
Whoa, Joe delivered the Murkle Circle to that guy naaamean