Frog
Frog legs are sometimes eaten as food in France, China, and the Midwest of the United States.  The killing of frogs might have an effect on the ecosystem. For example, frogs eat mosquitoes. If frogs are killed, then there are fewer frogs to eat mosquitoes, so more and more mosquitoes are born. Therefore, in these areas, there are more diseases that mosquitoes carry, because there are more mosquitoes. However, for this to apply, frogs would have to be a major predator of mosquitoes. This would only rarely be the case.