Oh, I'm pretty sure those are all Link's Awakening sprites, it looks like the Zelda version of the Blooper, plus a Ghini and Anti-Kirby. They definitely don't appear when playing the final game.Do these little ghosts and Blooper start appearing on the released version of SF2? Still haven't played it.
The rom is dated 1994-08-31 for what it's worth.
The CES named one (dated 1995-01-24) won't load for me, but perhaps someone will get it to work.
I did a quick check on TCRF ( https://tcrf.net/Proto:Star_Fox_2 ) to see if the graphics were at least included in the final game or in any of the other betas, didn't see them.