We had a lovely tom cat called Zeke. He had this big meow he'd make if you as much as looked at him, but I swear he had special meows for different occasions. When my mum got home from work (this was when I still lived at home) he'd run to the windowsil and do one meow at her until she came in from the car. There was one which almost sounded like "milk", sort of "meaaaalk", and another which sounded like my dad's name. I'm sure he didn't do it on purpose or try to mimic our voices but it was fun to imagine the sounds were actually words.
He also said "mowt" which we joked meant "I'm out" - he used to wait outsides the bathroom and if we were all getting ready for school, we'd say "I'm out!" after our turn brushing teeth, and he'd make "mowt" noises too.