You are in a position where both you and your opponent have the scarab god on the field and both of you have the mana to use its ability. When one person uses the ability and targets a creature card in the graveyard can opponent respond by using the scarab god ability on the creature they targeted to blank their trigger? I had this situation come up and it didn't feel right to me. I am a fairly new player though. I could very well be wrong.
Yes, that works fine. If one player targets something, the other player can, in response, target the same card. Theirs resolves first which means the first player's target is now gone and the ability will be countered. Note that the first player can pay the mana and activate the ability again if they want in response to the second player.
The Scarab God
Yes, that works fine. If one player targets something, the other player can, in response, target the same card. Theirs resolves first which means the first player's target is now gone and the ability will be countered. Note that the first player can pay the mana and activate the ability again if they want in response to the second player.