"Excuse me, are you Pöllölä?"
Translation:Anteeksi, oletko sinä Pöllölä?
"Anteeksi, oletteko te Pöllölä" should be accepted also. This is a polite way to ask someone whether they are who you think they are. In Finnish, this is known as "teitittely", which uses plural form to address single person to show respect. This is commonly used in formal occasions, customer service, and towards elderly people.