The UK electrical plug is a brilliant design with that one tiny drawback. And it waits for you, in the darkness.
That’s a d5. It has a square base.
I take all of those combined and go all in with a goat head. I grew up with those stuck in my foot. Now, it’s my dog whenever we are around them. And the definitely hurt as much as they look like they would.
Why didn’t you take them out?
He was too busy screaming and hopping around on the other foot.
I’ll bet his nickname was “Pogo”.
“Hopalong”.
Laugh it up ya bunch of comedians! 
They did break off and get stuck in your foot, or the dog’s paws which made them hard to get out (we went barefoot a lot and had “thick” feet). The only worse foot pain I had was stepping on a nail. Twice. I grew up on a farm in a rural area and those things happened.
When I was a kid, we called those hitch-hikers.
Listen to this guy. He knows whereof he speaks.
But he’s just a bag of tetanus shaped like Bob Dylan
At the risk of going even further off piste with regard to the topic at hand… what are they?! Are they thorns that have dropped off a plant?
Those are seed pods. “Designed” by Nature to catch & hold in animal fur (or feet) and be carried far and wide.
In SoCal we had a similar burr. Not quite so aggressive as goatheads, but plenty prone to attaching themselves to fur, cloth, or skin every time a kid went bushwacking.
cf:
Googling “goat’s head”, I think the picture is of Acanthospermum hispidum seeds.
Yes, as others have said, they are seeds that once they are ready to spread, dry out into really tough, evil devices. Most burs and gentle, cuddly things compared to these SOBs.
Growing up in my rural area, we called them Mexican sandburrs. And, yes, they hurt like hell when stepped on. It is a very aggressive invasive plant, and farmers would go to great lengths to keep them out of their yards and pastures, but it was a losing battle.
I thought those goats heads look somehow familiar, but I didn’t remember them being as vicious. TIL.
Aren’t those burrs the inspiration for Velcro?
Vivek Ramaswamy says he’s appearing in a live town hall on CNN this Tuesday.
CNN says no such thing is occurring.
There’s something seriously wrong with that guy.