A play by a defender of an apparently unnecessarily high card to prevent a throw-in on his partner. The defender needs to imagine being a crocodile as it opens its jaws to make sure of catching partner’s winning card (which by this stage is a singleton).
For example:
When South, declarer, leads a spade, West must play his ♠A, swallowing his partner’s ♠K. This saves East from winning and having to lead into the heart tenace.