English has so many irregulars. There are irregular verbs, of course, but remember that not every plural noun ends in “s” or “es”.
Only humans could create this.
Children (Child).
Teeth (Tooth).
Leaves (Leaf).
Feet (Foot),
Person (People, but even here there are exceptions to the exception).
Geese (Goose).
Mice (Mouse).
There are no mice in my house.