These creatures are from the AD&D 2nd Edition reference Spelljammer Appendix I.

Ancient Mariner (CR 4)

Dizantar (CR 8)

Fractine (CR 4)

Giant Space Hamster (CR 2) and variations (CR varies)

Plasmoid, DeGleash (CR 6)

Plasmoid, DelNoric (CR 3)

Q'nidar (CR 5)