plants that are OUT OF THIS WORLD (or look like it!)

[squid_ink]

Just throwing around some ideas for zone 5... someone I know is working on a garden where the theme is 'out of this world!' and is looking for full sun plants that look alien/unusual/otherworldly. I was thinking Echinops (Globe Thistle) looks pretty bizarre .. but for some reason I am drawing a blank. The temps here are dipping into the low 20s so I blame it on brain freeze

it's going to be in a bed so nothing TOO massive or invasive

anyone have any ideas? Again, it's full sun and zone 5. The weirder looking the better.

thanks!