do i still get otterpus passive if its dead or killed, then enemy scores

No. Otterpus's ability is a passive (replacement) effect — "If a player would score 1 point from conquering or holding during their first or second turn, they draw 1 instead." Passive abilities of permanents only apply while the card is on the Board (Rule 365.1), and replacement effects are applied at the moment the qualifying event would occur (Rule 370.1.c).

So once Otterpus is in your trash, it can't stop the enemy from scoring — they gain the point normally. The only way it applies is if Otterpus is still on the board at the exact moment the score happens.