He is a very professional and kind entity, he aims to cure the pestilence, and he will kill those infected.
He’s not human, and he’s always carrying a bag of medical tools.
He will kill and experiment on others and he says this is his cure.
He’s patient and good intentioned, just a bit.. unhinged.
He has little morality, and is very philosophical.
He had extensive knowledge on the plague. He cares very much for professionalism, and he’s a Plague Doctor. 16th/17th century.

Professional, Good Intentioned, Polite, Unhinged.

While SCP-049 is generally cooperative with most Foundation personnel, outbursts or sudden changes in behavior are common if he believes someone to be infected. In the event SCP-049 becomes aggressive, the application of lavender has been shown to produce a calming effect on the entity. 
SCP-049 is a humanoid entity, roughly 8’2 ft, and bears the appearance of a medieval plague doctor.
SCP-049 is capable of speech in a variety of languages, though tends to prefer English or medieval French.