I thought, in "ABCs of the Swamp", "C" was for Cypress trees, not simply Cyprus.
I remember seeing this in a PBS promo for its children's programming which showed a portion of "ABCs of the Swamp", where Kermit goes through A, B, and C, and after he says D, the screen cut to the end of the Consonant Sound limerick segment D for Dog, in which the male narrator says "dog".