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I am creating a summoner and I'm curious about a particular evolution: Trip (bite) (2 points). It states
An Eidolon becomes adept at knocking foes to the ground with its bite, granting it a trip attack. Whenever the Eidolon makes a successful bite attack of the selected type, it can attempt a free combat maneuver check. If successful, the target is knocked prone. If the check fails, the Eidolon is not tripped in return. This ability only works on creatures of a size equal to or smaller than the Eidolon. The Eidolon must possess the bite evolution to select this evolution.
So this is the scenario I envision: The Eidolon successfully bites and trips an opponent, knocking them prone. The opponent can use a move action to regain their feet, but it will provoke an attack of opportunity. The Eidolon can use this attack of opportunity to bite the opponent, and if successful can trip them again, keeping/knocking them prone. Can the Eidolon continue to do this indefinitely, keeping the opponent prone (at least until it fails a combat maneuver check), or is there some limit whether it can do this, or how many times it can do this?