I remember.
Does anyone remember Pandamonium?
Here is the synopsis:
When an evil alien named Mondraggor (voiced by William Woodson) attempted to steal an ancient object called the Pyramid of Power, the pyramid shattered into many pieces, which scattered around the world. Each week, Mondraggor would race against two human siblings, Peter and Peggy Darrow, who were accompanied by three talking pandas named Chesty, Timothy, and Algernon, who were irradiated by the Pyramid's magic. The three of them can unite to form Poppapanda, a being with supernatural power.[3]