(archon, extraplanar, good, lawful)
Source: Monster Summoner's Handbook, pg(s). 24
A codex archon takes the form of a very large book with wings made of light. The book is functional and contains all knowledge the archon has collected regarding its specialty.
Each codex archon focuses on a specific topic or field and seeks to record all information about that topic in its pages.
Codex archons prefer their homes in Heaven's libraries, but can be summoned to serve in Material Plane libraries, schools, and temples. While many contain information of great value in combat, codex archons avoid violence.