A "cobra trainer" is a person who always one ups you by saying they also did it or did it better or did it more often.
Tammy: Stephanie is such a cobra trainer!
Tiffany: Why, what did she do now?
Tammy: I told her about my visited China and was giving her the highlights of my trip. She said she's also been to the same places and claimed to have been to many other.
Tiffany: That's possible.
Tammy: She's never even been to China!
When you wash your fresh cobra meat off before the big Sunday night fry-up.
Hey Uncle Neck you there? Oh sorry Jafar I was too busy to listen to your story as I was at the sink making sure the fresh cobra meat is ready for the big Sunday night fry-up.
Oh no worries Uncle Neck, the Cobra Rinse is more important than my story about the time I forgot to do a Cobra Rinse and got Cobra Worms at the big Sunday night fry-up.