The villagers
The witch came to the dungeon to check on the two captives. When she arrived she found Elena and Esteban sleeping peacefully. The two of them were enjoying a nap without any worries.
The man who led the team into capturing them informed her that they may be more to the two of them than just being werewolves. He showed the dead body of the man Esteban and narrated to her how the man died.
The witch examined the man's body and looked at the captives with shock. "Tribrids," was all she said to the man.
"Can you prepare a poison that works for them?" he asked her. The witch left the village head's house and headed over to her home. She went to her spellbook to look for a spell that might work on a tribrid.
"Take this to the village head," she said to the little boy who stayed with her. The boy took the bottle from her and ran to the village head's house to give it to him as the witch had instructed.