Graphics created by Carlos Abril for Wiz, an unrealized project for the Amstrad CPC prior to Phantis.
Some of these graphics were the basis for others which he would use later:
Carlos Abril
On that screen you can see a dragon that was in the first version of Phantis, and I think the floor and walls are the same which that first version had.Source: GamesTM Spain #4
He likely refers to the dragon which appears in the second line of this page: