Teodor is a resident of Burgh de Rott, a small town in southern Morytania, which can only be entered once the In Aid of the Myreque quest has been completed.
He disappears after The Branches of Darkmeyer is completed, causing Amelia to note that he has gone missing. A missing person poster also appears south of her, which reads "Missing: Teodor - has he been harvested?"
He appears again during River of Blood near the end of the quest, being one of the vyrewatch who revert back to human form when crossing the newly blessed Salve River.
This information has been compiled as part of the update history project. Some updates may not be included - see here for how to help out!