  A dozen of patches of polarized radio emission spanning tens of degrees in
the form of coherent and stationary loops are observed at radio frequencies
across the sky. Their origin is usually associated to nearby shocks, possibly
arising from close supernovae explosions. The origin of the radio Loop XII
remains so far unknown. We report an anti-correlation of the radio polarized
emission of loop XII with a large patch of soft X-ray emission found with
SRG/eROSITA in excess of the background surface brightness, in the same region.
The soft X-ray seemingly coherent patch in excess of the background emission,
which we dub as the Goat Horn complex, extends over a remarkable area of $\sim
1000$ deg$^2$ and includes an arc-shaped enhancement potentially tracing a cold
front. An anti-correlation of the X-ray intensity with the temperature of the
plasma responsible for the X-ray emission is also observed. The X-ray bright
arc seems to anticipate the radio loop XII by some degrees on the sky. This
behavior can be recast in terms of a correlation between X-ray surface
brightness and radio depolarization. We explore and discuss different possible
scenarios for the source of the diffuse emission in the Goat Horn complex: a
large supernova remnant; an outflow from active star formation regions in
nearby Galactic spiral arms; a hot atmosphere around the Large Magellanic
Cloud. In order to probe these scenarios further, a more detailed
characterization on the velocity of the hot gas is required.
