Instead of saying "Purr" or "That was so purr", you cram the idea of the purr sensation you feel into one word.
You just won a million buckaroos? Purrdat mama gurrz, you ate dat all the way uptown for realz or whatever.
*whiteman looks my way for 0.000000001 second, me in my head* "Oh, you like me?" *in my head I'm creaming my pants but I gotta be professional* "Purrdat" he responds, "huh?"