(noun) When your legs fall asleep from sitting on the toilet for too long taking an epic dump.
After sitting on the toilet for 45 minutes, I found that I had developed dookie legs and had to hobble around like an old man until the feeling came back.
The act of sneaking/crawling up behind someone… (usually if they are walking over/past dog poop or something brown and vaguely turd shaped, but not always!) …suddenly wrapping your arms around their legs and tackling them to the floor, always accompanied by a shout of “Dookie legs!”
My brother dookie legsed me when I was walking past the compost heap and now I’m covered in mud and rotten fruit.