Runny Babbit: A Billy Sook is the title of the last children's book by Shel Silverstein. A work in progress for the better part of 20 years, the book was published posthumously in 2005. The book is largely composed of spoonerisms in rhyming verse; e.g.:

Runny Babbit knearned to lit

And made a swat and heater

And now he sadly will admit

He bight have done it metter

Way down in the green woods where all the animals play

They do things and they say things in a different sort of way

Instead of sayin' "Purple hat"

They say, "Hurple pat"

And instead of sayin' "feed the cat"

They say, "ceed the fat"

So if you say, "Lets bead a rook"

That's as billy as can see!

You're talkin' Runny Babbit talk

Just like mim and he

Runny is a normal child, with many friends and two loving parents, his "dummy and mad" - who urge him to "shake a tower" and things like that.