Of course, my horse

There is no other expression that depicts the playfulness of Chilango speak better than this one. "Of course, my horse" means "by all means, buddy". It is not offensive but it is very informal. 

Mexicans take English courses all their academic life (K-12). Among the handful of expressions and words that stick is "of course". Since no Mexican would consider fun such a dry expression, a rhyming companion is added: "my horse". It doesn't imply that the listener is a farm animal that needs to be ridden on the back. Not at all. It just rhymes. "Of course, my horse" is equivalent to "mos def".

Example:

Poncio: ¿Ya calaste al Instituto Mexicano del Sonido?
Pilatos: Of course, my horse. Esos broders si se rifan.

Poncio: Have you listened to the Mexican Institute of Sound?

Pilatos: Mos def. Those dudes are awesome.