A bot can be assigned with the command /bs assign #channel botname. These bots are publicly available to users:

Arceus           (Arceus@the.original.one)
Azzurra          (bot@come.clarity)
Commander        (bot@bitsjointirc.net)
DarkKnight       (DarkChaos@Dark.Fangs.Dripping)
Final-Shine      (DBZ@Pwnage.Attack.of.Death)
Gyarados         (RAGE@Atrocious.Water.Pokemon.Since.1996)
Kakashi          (Sharingan@For.The.Moonlight)
KuroNeko         (the@cute.kitty.bot)
MuffinBot        (muffin@so.tasty)
NyanServ         (nyan@nyan.cat)
OfficerJenny     (jenny@hold.it.right.there)
Sensei           (Sensei@nihongo.wo.benkyou.shimashou)
SkyNET           (Cyberdyne@Global.Digital.Defense.Network)
Viper            (Snake@The.Apex.Predator)
Wheatley         (wheatley@Aperture.Science.Enrichment.Centre)
Yuki             (yuki@integrated.data.sentient.entity)