Final answer:
The serious character described would be an excellent 'foil' for the clownish comedian, as a foil contrasts with another character to highlight their traits.
Step-by-step explanation:
With his serious face and his dignified way of speaking, he is an excellent foil for the clownish comedian. A foil is a character that contrasts with another character, usually the protagonist, to highlight particular qualities of the other character.
Given the serious demeanor of this character, he would provide a sharp contrast to the clownish comedian, thereby serving as a foil, which emphasizes the traits of a main character through contrast. The foil will often be the complete opposite of another character, allowing the audience to see important traits in the main character more clearly.