  3C 275.1 is a blue quasar at $z=0.55522$, hosting powerful outflows and
residing in a complex environment. We present a serendipitously detected giant
nebula surrounding 3C 275.1, which shows morphological features resembling
those of objects known as "jellyfish galaxy", with extremely long tails of
ionized gas extending to 170 kpc in projection. We analyze its optical spectra
taken by the MUSE on the VLT. The brighter part of this giant nebula exceeds
100 kpc, whose rotation curve does not flatten out, is very different from
those of normal spiral galaxies. This system shares some characteristics common
to those formed via ram pressure stripping (RPS), yet its long narrow tails and
higher ionization are unusual compared to known tails in jellyfish galaxies,
not fully consistent with a simple RPS scenario. Our photoionization simulation
and the inferred short recombination timescale both suggest that besides the
quasar 3C 275.1, an extra source of ionization is necessary to keep the gas
ionized at such distance from the nucleus, which could be related to RPS, tidal
interaction or AGN outflow, providing new evidence of active dynamical
interaction of a galaxy with the intracluster medium.
