Teeny Cactus

Some folks might be used to seeing teeny, tiny cacti, especially in pots.  This one isn't in a pot.  Somehow a seed must have blown against the edge of the patio and it began to grow there.  I noticed it about six weeks ago.  Now it's about two inches tall. Looks like some poor bird lost a feather, too, which got caught up in it.  I'm going to have to dig it out soon, possibly replanting it.  It sure can't stay where it is!