That's actually quite...hilarious. That is one venomous snake (a juvenile can easily kill a person several times over, plus their bite often barely registers to people as they have tiny fangs; a gift and a curse there). Lucky for you, and lucky for your cat too. They're fairly docile, and if they're cool, they'll be slow; they'll rather flee than fight unless backed into a corner and/or provoked.
There was one about the same size and coloring in our house several months back. I removed it.
Watch where you step in your yard (standing on such is a common cause of being bitten).