"Liverpool Lullaby" by Stan Kelly (aka Stan Kelly-Bootle). Recorded by Judy Collins in 1967 on In My Life. It's a straight lullaby until a line late in the song that cracks me up: "and I'll buy your daddy a brewery".

I think it deviates from being a lullaby a lot sooner than that.

"Sure you are a mucky kid,
Dirty as a dustbin lid.
And when he hears the things that you did
You'll get a belt from yor Da"

Child cruelty!