Bill--it's just a cottontail rabbit--one of many that hang around the yard. It looks lanky (like a hare) because it's stretched out on "tip-toe".
Speaking of "bunnies" and hard-to-kill cacti, I'm trying to eradicate an invasive, non-native Opuntia called "bunny ears" that has taken over parts of the yard. I uprooted several of them in February and left them, roots on the surface, to dry out in the sun. I just went out to check it, and sure enough, it's still doing just fine. If I don't do something to kill it, it will send new roots into the ground when the summer rains hit.
If you leave a single pad flat on the ground (the one in the photos was dropped there in February as well) it will curl up like a dish in the sun, which gives it good soil contact on the bottom. When it rains, the "dish" traps water, absorbs it, sends out new roots from the bottom, and starts shooting out new pads from the edges. (I flipped this one over to show the healthy green of the underside.)
A former co-worker said he left a pile of them on a concrete slab in the sun for over a year, and they just wouldn't die--they formed new pads, bloomed, and produced fruit till he gave up and put them in the trash can.