>>51839926An DP-era marketing interview mentioned how a "sea-slug Pokemon" had been cut from RS and later brought back for DP. RS has two unused cries that sound like they could work for Shellos and Gastrodon, and the data for DP has unused backsprites for the two that seem to predate their two form gimmick, incorporating elements of both.
All of this information predates the Gigaleak, so it's not as flashy, but it's about as definitive as we'll ever get.
