Mystery kitty looking in the kitchen window sticking his tongue out at me.

I think he might belong to the neighbor's to the south of us, but this kitty has been coming around mournfully meowing at dawn, peaking in the windows at all hours of the day and night, and driving our kitties crazy. He's a really handsome kitty, and he acts like it wants to make friends, but the second he sees us move toward the door or if I talk to him through the open kitchen window, he's off like a shot. 

Spunk is very worried about this new cat on the block, and in an effort to protect the household from this invader, Spunk has been marking his turf and securing the perimeter.

Mystery kitty sitting out in front of the kitchen window posing for me.

He sits on the deck and looks in through the glass in the door, but he runs the second he sees either of us coming to the door.

Spunk "The Urinator" reloading at the bathroom sink

Pissy cat Pissy cat where have you gone?
Securing the perimeter from dusk until dawn
Golden beads tumble down surfaces standing on end
From the shake of your tail and the squirt that you send
Saving us from the new cat on the block
Marking your turf, if you could only use chalk
Pissy cat Pissy cat where did you go?
Forget that question I really don’t want to know

Loki in the catio

Loki

Marble playing with her mouse and bouncing off the walls

Sasha with egg cartons

Silver in cat food box with egg carton