The huge hippo weighs almost three quarters of a tonne and is around two metres in length.
It was taken from the Chilstone site, which is located in Fordcombe Road, Langton Green.
Police are investigating the theft, which is believed to have taken place between 5.30pm on Wednesday 9 January and 7am the following morning after entry was forced to the site’s show gardens.
PC Nick Lingham from Kent Police Rural Taskforce team said: “The hippo is extremely heavy and in the past it has taken five people to lift it.
“It is clear those responsible would have needed a large vehicle such as a flatbed truck and may have also needed to lift it by mechanical means.
“It is a hugely distinctive object and it is unlikely the offenders will find it that easy to sell on as scrap or to a collector.
“Because of its sheer size we are hoping people may have seen it being transported and also asking members of the public to keep their eyes open and report anything suspicious.”
Anyone with information is asked to call Kent Police on 01622 604100, quoting reference 10-0236. Alternatively, contact Kent Crimestoppers anonymously on 0800 555111.