Deity summoned at the end of the previous floor, whose confused arrival Khepri's mirrors exactly.
When the bug god chittered angrily inside the Temple of Khepri, apparently confused why everything was stopped and who all these intruders were, Carl recognized the behavior instantly: it was the same as it had been with the Vinegar Bitch at the end of the previous floor.
The comparison tells Carl what to expect from a freshly summoned deity — disoriented at first, then dangerous, exactly as The Announcer promised Khepri would be once the countdown expired.
Precedent for how a summoned god behaves on arrival, referenced by Carl mid-trap.
Also appears in books you've already read — spoiler-safe to their endings: