Egypt Walking Onions, or Egyptian Walking Onions, are easy to get and once you plant them, you have them forever but you have to contain them or they will fill your garden. If you planted some in your front yard, your whole front yard would eventually be these onions. Some people put metal into the ground around the onions to keep them where they want them. Others use a separate plot for the onions so they won't go into the regular garden. I'll put mine in a wood planter box on the ground and if they try to walk over the box onto the garden ground, I've said I would yell at them to get back in their house and if that didn't work, I'd trim back the ones trying to escape - just trim them back past the wall of the planter.
A fellow Freeper will send me a few. The very best website for these onions is below and you can order them from these people. Here is the link starting on the page with the pictures of the onions in their life cycle:
http://www.egyptianwalkingonion.com/photogalleryonionpatch.htm