An adventurer card is a permanent card in every zone except the stack, as well as while on the stack if not cast as an Adventure. Ignore its alternative characteristics in those cases. For example, while it's in your graveyard, Ondu Knotmaster is a white and black creature card whose mana value is 4. It can't be the target of Pinnacle Monk's last ability ("When Pinnacle Monk enters the battlefield, return target instant or sorcery card from your graveyard to your hand").