  We study scalar test-field perturbations on top of a Kerr--black-bounce
background, i.e. a family of rotating regular black holes and/or rotating
traversable wormholes that can mimic Kerr black holes. We compute the
quasi-normal modes for a massless field in both the regular black holes and
wormhole branches, confirming the stability of the former and identifying a set
of growing modes that renders the latter unstable. We further compute the
superradiance amplification factors, for massless and massive fields, in the
regular black hole branch, confirming that these objects superradiate, though
to a lesser degree than the corresponding Kerr black holes.
