The Elefant (German for “elephant”) was a heavy tank destroyer used by German Wehrmacht Panzerjäger during World War II. It was built in small numbers in 1943 under the name Ferdinand, after its designer Ferdinand Porsche, using tank hulls that had been produced for the Tiger I tank requirement, which was rejected in favour of a Henschel design.
In 1944, after modification of the existing vehicles, they were renamed Elefant. The official German designation was Panzerjäger Tiger (P) and the ordnance inventory designation was Sd. Kfz. 184.
Source: Ferdinand on Wikipedia