What's more, homeowner Kayla Slaughter of Boulder lost her beloved house cat Klondike to the intruder, which sauntered in Wednesday night and stayed uninvited for several terrifying hours.
"That is hard, that it's the end that she had," Slaughter told KDVR.
Slaughter was also terrified for her own life and watched in fear as police shot beanbags at the windows in a bid to scare the beast off.
Eventually, their work paid off and the mountain lion left the house and crept back into the woods.
Boulder police issued a warning following the incident, urging residents to take the same precautions with wild animals as you would with potential thieves.
"Please keep ground level doors and windows closed and locked at night and when you are not home. (This is also good advice for bears and burglars)," the statement reads.