Who knows what these guys were up to? They were murdered by the Happy Homos.
When the Happy Homos see someone they don't know, they typically just kill them. In this case, Davorin did know them, so they were double killed. They believed that they possessed a magical skull that allowed them to control the Young Green Dragon, Venomfang.
The Happy Homos encountered them in Thundertree, locked them inside their house, threw in three liters of dragon's breath, then cast an Eldritch Blast inside, killing everyone in a matter of moments.