Super Smash Bros. Sonic Mod is another fan-made modification to the original Super Smash Bros. for Nintendo 64, similar in nature to the "Sonic 2 Mod." It focuses on integrating elements of the Sonic the Hedgehog series into the game.  It probably adds Sonic characters as playable fighters and potentially new stages or items related to the Sonic games.  Being a fan project, its content is not standardized.

Super Smash Bros. Sonic Mod

Super Smash Bros. 19XXCE