wild boar, to fight
豦 centers on a wild boar and the aggressive fighting associated with it. The meanings are linked by the image of a fierce, combative animal.
豦 combines 虍 (tiger stripes) and 豕 (pig), suggesting a fierce pig-like animal. The exact historical development is uncertain, but the combination likely depicts a wild boar with a tiger's ferocity.
A tiger-striped pig (虍 over 豕) charges out of the forest: it's a wild boar ready to fight.
For キョ, imagine a wild boar letting out a loud 'kyo!' squeal as it fights: kyo -> キョ.