Rouge the Bat was considered for all three Sonic films. For whatever reason, the writers have just never been able to make her work. Big the Cat almost made a cameo too... as a skeleton in the second movie.

As more characters join the Sonic the Hedgehog movie series, fans have been curious when their favourite big cat - Big

During the Siberia sequence in Sonic the Hedgehog 2, one draft included a riff on Raiders of the Lost Ark, specifically the moment from the opening where Indiana Jones springs a trap and reveals the corpse of a rival adventurer. Only, instead of a human body, Sonic would have been confronted by the skeleton of a cat. A big cat.