The New Adventures of Robin Hood (1997) : 4x11

Elvis, a descendant of Barkley's, appears from the future in a time machine, interrupting a battle between Robin's band and Lord Rudolph's band of marauders. The marauders steal the time machine, but it will explode with unimaginable destructive power if it is not returned to the time it came from within 24 hours. Rowena befriends Elvis, and they fly through the forest on magical skateboards to escape the marauders. Robin races to return Elvis to his own time before disaster.