The Viper

A woman was sitting alone in her flat when suddenly the phone rings.

She picks it up: "Hello"
Stranger: "I am the viper"

Instantly, she hangs up -feeling anxious and slightly nervous
The phone rings again

Woman: "Hello, who is this?"
Stranger: "I am the viper, I will be upstairs very soon"

This time, the woman is panicking and she's preparing to call the Five-O.

Finally, the phone rings again:
Stranger: "I am the viper, I am almost at your room"

This time the woman was dialing for the police, until someone knocked on her door.

She approaches cautiously and grabs a knife. Then shouts; "I've called the cops. Whoever you are, you better run or else....."

The lady opens the door and sees a short, old man.

The man replies, "I am the viper, I am here to vash your vindows."