So I searched the files of the Zelda: Four Swords Anniversary Edition ROM for unused sprites hoping to find the beta Link sprites, but actually I found some unused sprites:
From top to bottom:
Beta Keese: Keese sprite with a lot of colors and detail, instead of it being just a black bat figure.
Beta Zol: Didn't test the animations so I put the ones that share similar frames in rows.
Great Fairy: A beta great fairy that uses the OOT design, it's really cool to see a MC-styled great fairy, also with great animation.
Note that none of these have their palettes so I gave them modified colors from MC for viewing pleasure.