When this creature enters, you may exile a creature card from your graveyard. When you do, return target instant or sorcery card from your graveyard to your hand.
原文You don’t choose a target for Kishla Trawlers’s ability at the time it triggers. Rather, a second “reflexive” ability triggers when you exile a creature card from your graveyard this way. You choose a target for that ability as it goes on the stack. Each player may respond to this triggered ability as normal.