Oli, the middle child in the TV series Les Parent, breaks the bad news to his father that he’s failed his exam at school. When his father gets upset, Oli defends himself by bad-mouthing his teacher:
C’est un vrai malade!
He’s really crazy!
Informally, Oli pronounced c’est un as c’t’un, as though it were one word.
In addition to meaning “ill” in the physical sense (like when you have a cold), malade can also take on the meaning of “crazy” during more informal conversations:
T’es malade ou quoi?!
Are you crazy or what?!
[Quote said by Oli in Les Parent,“Question existentielle,” season 4, episode 18, Radio-Canada, Montreal, 27 February 2012.]
Interesting. What really has me puzzled, is how he refers to his teacher. I would have guessed “Il est…” intstead.
Compare:
C’est un avocat.
Il est avocat.
… or using malade:
C’est un malade.
Il est malade.
You can read more HERE about c’est and il est.