Good Boy is a secret achievement in Immortals of Aveum. You can only unlock it during Chapter 16 of the main story campaign. When playing the “Glaivegate” mission, you need to rendezvous with Zendarra at the wall. There you can find a Veki amongst the survivors of Sandrakk’s attack.
You can find the Veki on the bottom floor inside the stronghold. The animal is located in the left area, so make your way down the stairs and turn right. Veki is hidden in some of the wooden crates that are against the side wall.
You need to interact with the animal in order to trigger the achievement.
