Mix brownie mix according to manufacturer directions. Line a half sheet tray with parchment paper and treat with pan spray. Deposit 3 pounds batter, spread to edges, and bake at 350F until set. Let brownies cool completely then freeze. Unmold and cut while frozen (this step is optional, but the brownies will both unmold and slice much easier from frozen). Melt white chocolate and drizzle on each brownie, place two eyeball sprinkles while chocolate is still warm.
If eyeball sprinkles are unavailable, simply pipe a bit of white coating chocolate in a circle and top with a dab of melted chocolate for the eyes.