Write SQL query to solve given problem: What's the avatar image of the user who created the movie list "250 Favourite Films"?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.user_avatar_image_url FROM lists AS T1 INNER JOIN lists_users AS T2 ON T1.list_id = T2.list_id AND T1.user_id = T2.user_id WHERE T1.list_title = '250 Favourite Films'