The best way to learn proper English is to read news report, and watch news on TV. Watching TV shows is a great way to learn casual English, slang words, understand culture reference and humor. If you have already watched these shows then you may recall the words used in the following dialogs.

Mutt.
Money Heist Season 3, Episode 5

And you, MUTT, you will stay silent.
Did you hear me?
Money Heist Season 3, Episode 5

I mean, everybody loved that MUTT
Breaking Bad Season 5, Episode 12

Hey, MUTT!
Money Heist Season 3, Episode 5