Probably in reference to king kong. This move is sometimes known as the
monkey vault. It is performed by placing the hands on an obstacle in
front as one jumps up and over. The feet generally come up between the
hands as one clears the obstacle.
Kong gainer pre
Jumping over the first wall is the kong. The flip while traveling in a
forwards direction makes it a gainer. We add the modifier suffix 'pre'
because of the precision landing on another wall. An impressive trick.
@calen_chan