Just a variation on the "Earth Anchor".

I've had coyotes eat in half 2 plus inch hardwood trees when in traps.
I would never trust a wood stake to keep a coyote in place,
Cable stakes are cheap and can be reused if you dig a little before pulling them after trapping.
Cable stakes are even cheaper, if you buy the components and make your own.

I used wood stakes years ago and never lost an animal because of them. When coyotes showed up here I gradually started replacing wood with rebar. Still did not lose a coyote with a wood stake.
But like was said earlier you can have problems driving wood stakes because of splitting. Rebar is great because you can flail the heck out it and get it drove without fussing with it and having trouble.
I use a lot of cable stakes nowadays. I'm not getting any younger and I really like not having all the weight of rebar, though I do still use some rebar.

wolf fang anchor kit, 5 dozen anchors, cable, ferrules, and driver $45, only tools you need are a cable cutter, either hammer or swager.

How was it they were making disposables out of conduit?
The way I remember it is cut it to length, drill one hole in the middle, run the cable thru the hole then put a stop on that end of the cable.
Would be a good deal for someone who doesn't want to spend much $.

There it is!! I skimmed right past it. Jeez!!

I've been thinking about this and have a couple suggestions. A little backround first...I survey for a living and I can tell you that a 12" long 1.5"x1.5" stake pounded in flush is a real bear to pull out. You need to dig it about half way, then wriggle it pretty seriously to get it to come out. That being said, try this:

Use a cable that is about the same length as you wood stake (at least 12"), with loops at each end. Place the point of the wood stake in one end loop (make sure the loop is smaller than the wood stake), then drive ththe stake/cable into the groun-flush. Attach your trap chain to the other loop. Use a swivel right there where you connect. That stake will not come out. With the lateral pressure put on by the Coyote(the pressure will be put on the point (bottom) of the stake, not the top), the stake will act like a large earth anchor type stake...won't move the top of the stake and loosen the hole as someone mentioned before.

That should solve the 'how to connect' and 'enlarge the hole' questions. I would feel comfortable using an 18" 1"x1.5" stake as well. All you'll need is a 3 pound hammer in most cases. Longer stakes will work in sandy soils. Better use rebar if ground it frozen.

Hope that helps...Ken