1988, Denise Ohio, The Finer Grain, Naiad Press, →ISBN, page 23,
He'd look at me sort of sideways and say all the time, you're losing it, Amy, honey, you are going looney tunes.

2002, Tony Spivey, Covered Ground, Iriswhite Publishing, →ISBN, page 12,
I thought him crazy. / Pure looney tunes.

2004, Lee Driver, The Unseen, Full Moon Pub., →ISBN, page 35,
"Well, you should have found out if she was looney tunes first."

Although almost certainly suffering from manic states and perhaps from a form of manic-depressive illness, Dad could not be effectively diagnosed. He was what people might describe as either crazy as a bedbug, totally Looney Tunes, three sandwiches shy of a picnic, or an abusive manipulator.

Looney tunes

Meaning

Adj