re: Biggest assholes in the animal kingdom

The cuckoo.


They lay eggs in other birds nests.
Then their eggs hatch earlier and the chicks know instinctively to push the other eggs out of the nest.
Then their cries are designed to mimic the cries of multiple chicks of other species so the parents come with food for multiple chicks.

Cuckoos are the arse holes of the animal kingdom
The cuckoo with David Attenborough