This question might need to be moved to the discussion board for more than one answer, but I think most people would say shooting a cat is worse than shooting an elephant. Elephants are large and could possibly be dangerous in certain situations. While both species are intelligent, an elephant would certainly pose a greater threat than a cat.
Of course, the word pathetic could have other implication behind it. You might say it's more pathetic to shoot an elephant because it provides an easier target. Looking at it purely from a hunting perspective, one might say it is more of a challenge to shoot a cat than to shoot an elephant. Although, I would imagine that the thick skin and shear size of an elephant would provide challenge enough.