this italian word has a double meaning.
1. crude for "gay", "faggot
". Literally it means "huge-assed man".
2. Lucky guy. In italian "che culo!" (ke kooloh) means literally "what an ass
!" and means "Great luck!". So culattone means "lucky guy". As its referred to definition 1., often it's used to underline one's luck adding a personal envy in it.
You got a ticket to see the derby? Che culattone!
1. Guarda come si muove! Che culattone!
Look how he moves! What a faggot!
2. You got a ticket to see the derby? Che culattone!