If you discard Dodecapod and put it onto the battlefield, you've still discarded it. Abilities that trigger whenever you discard a card will trigger.

If the spell or ability that caused you to discard Dodecapod refers to "the discarded card" or similar, it refers to the Dodecapod on the battlefield.

If a spell or ability an opponent controls causes you to choose a card to discard and you discard Dodecapod, you'll put it onto the battlefield.