The Nazi graffiti was drawn on the impressive artwork, which sculptor Dan Hilton spent several days creating last year in the Victoria recreation ground.
The mindless yobs have even added a crudely drawn cigarette protruding from the baby's mouth and a "tag" scribbled on its neck in permanent marker, which is the graffiti artist's signature.
A swastika and Hitler moustache were scrawled on artwork in Victoria recreation ground
Dan, 40, who sculpted the masterpiece to promote his work, says: "It's a real shame, but unfortunately these things happen. It was probably kids.
"I don't know why they do it, but it was probably a kind of scent-marking.
"It's not particularly enlightened, but these aren't particularly enlightened people."
Despite the extent of the damage, Dan is confident he will be able to remove the graffiti and restore the sculpture to its former glory.
He said: "I can sort it out, no problem. I just need to carve the graffiti out and oil it over again. It'll take about a day."
The vandalised carving in Victoria recreation ground in Canterbury
The carving mysteriously appeared in the trunk of the dead tree last March, which the council was planning to chop down.
Dan managed to intervene before the chainsaws were brought in and persuaded the authority to let him create something beautiful.
It has since proved to be a talking point for admirers.
The self-taught sculptor said: "Everybody absolutely loves it, and thinks it's brilliant. People have been so supportive."
Daniel Hilton carving the tree at Victoria recreation ground in Canterbury
Dan, who lives in Rough Common Road, is also responsible for the sculpture on the plinth outside the city council's offices in Military Road.
Council spokesman Rob Davies said: "The graffiti has been reported and as some of it is of an offensive nature it will be dealt with as soon as possible."
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