Engelbert Sneem and his dream vacuum machine, written and illustrated by Mr. Daniel Postgate
Oh, awesome! It's a fun, good-looking book that, very sneakily, is also for helping with nightmares! Mr. Sneem is like a reverse Santa Claus who shows up and suctions away the dreams of children, keeps them corked up in brown bottles for his own consumption. Then one night a mom reads her kid a bedtime story - a book about Engelbert Sneem (ooo! meta!) - and the kid has a nightmare about him. Sneem sucks up the kid's dream and then views it at home. He is so upset to find out that he himself is a nightmare that he vows to change his ways.
if a child has frightening dreams
Of ghosties and ghoulies
and terrible things,
The good Mr. Sneem
is right there in a tick,
And he sucks up the nightmare
and plugs it up quick.