The giant blow up clown was on the grounds of a private residence when it was sliced up overnight on Tuesday.

It comes after promotional signs the circus put up around the city were also defaced with "animal cruelty" messages.

"It's pretty nasty," Circus manager Julie Petersen said of the latest attack.

"Why would you do something like that?"

Ms Petersen said she was unsure if it was a targeted attack or just mindless crime, but implored whoever slashed the inflatable to front up to the circus and talk to the people involved in it.

"We're a family circus, we love this town," she said. "We're hopeful the people of Maitland will come out and support us.

"It's just disheartening people would do this."

The circus has its first show in Maitland on Thursday and is in town until March 22.