^I think this answer has already been answered, but worded differently.
Here's what I think:
Pidgy eats worm-like or Bug Pokèmon, such as Catterpie
Heatmore eats Durants
Magikarp to all those Pokèmon willing to eat it, example, Pigeotto
In human world:
Bug type Pokèmon, because they're delicious (...)
Magikarps and all those fish-like Pokèmon
Bird-like Pokèmon's eggs
Chicken-like Pokèmon (so sorry Torchic ;-;)
Farfetch'd meat (ohh how the cruellllteh)
Eh... That's all I could think of...