This Solar Auxilia Medusa was in the display cabinets at Warhammer World.
The Medusa artillery tanks employed by the Solar Auxilia are armoured bombardment platforms, their heavy guns mounted on a hull derived from the Leman Russ. Enclosed against enemy fire and protected from the hazardous atmospheres of toxic or alien worlds, these mobile siege batteries can keep pace with the cohort’s advance, pummelling the foe’s positions even as main line units move to engage any survivors. The Medusa’s mortar fires munitions heavy enough to shatter mighty walls.
I much prefer the original Imperial Army Medusa, however that model appears to have been retired.