Who is A. Bettik from The Rise of Endymion and what is their importance?

A. Bettik is believed to be a member of the race of androids built in the early days of the Hegemony, which were later outlawed. In actuality, he is an Observer from the Lions, and Tigers, and Bears. Present throughout the saga, Bettik was first a member of the crew on the manta boat that transported Hyperion pilgrims on the first leg of their journey, and he was later in the service of the poet Martin Silenus.

In his guise as an android, A. Bettik is a bald humanoid with cobalt blue skin. He is nearly impervious to extremes of temperature and can go long periods of time without oxygen.