The handmade Chatto Creek letterbox disappeared on Saturday night during Labour Weekend.
Simba's owner, Stephen Price, of Chatto Creek, said it was not the first time the pink elephant had gone "on safari".
The local landmark, on State Highway 85 between Alexandra and Ranfurly, also "disappeared" about eight months ago.
After an educational visit to the University of Otago campus in Dunedin, it turned up again.
"The whole road has different-themed letterboxes, including tractors and snails.
''They enhance the area and when people ask directions to our house we tell them to look for the pink elephant," Mr Price said.
Sergeant Ian Kerrisk, of Alexandra, said the disappearance was "very disappointing".
"It is especially frustrating to see incidents like this occur."