- Available in Clockwork City – Act 1.
When initially summoned, Arcanaeum Librarian's usefulness is unimpressive, and its low health makes it an easy initial target. However, Arcanaeum Librarian gains 1 point of power every time its summoner draws a card on their turn. This includes the card drawn at the start of the turn but does not include cards drawn from a rune being broken. For decks that feature the ability to drawn more cards than is typical, whether by actions and Summon keywords or creatures with Pilfer, Arcanaeum Librarian can become tremendously powerful.
As with other cards whose strength relies in accumulating power or health over time, summoning Arcanaeum Librarian in the Shadow Lane when available will increase its early survivability by preventing it from being attacked the next turn. Using other creatures with Guard in the same lane as well as giving it a Ward will provide more opportunity for Arcanaeum Librarian to grow in power.
- Arcanaeum Librarian portrays Urag gro-Shub from The Elder Scrolls V: Skyrim.
- Arcanaeum Librarian is the only Orc with an attribute other than Strength or Endurance.
- The card was orignially named "Arcaneum Librarian" (missing the second "A" in "Arcanaeum"), but this typo was corrected in a later patch.