The quotes around “Dog” are nice touch

Bonus points: if someone asks about it, say that the bark is worse than their bite!

If someone asks about it, just start to say “Oh, he’s right-” then just stare at the fence for a moment before looking worried and quickly removing the sign and locking your door.

All that is missing is a picture of a chihuahua under the sign :)

Say, where can I get a cerberus?

Is it the beast from The Sandlot?

Just straighten it yourself so it would look somewhat okay but janky. That way you would never have to remove that sign.

Well … some are very real: https://www.youtube.com/watch?v=X8BQf-KdOfQ