Seeing the new video of it and... I predicted the Bubble Mario apparently, except it isn't a reverse physic Fire Flower but more a straight shoot, but well, both are related to bubbles.
Bubble Mario which has is a reverse physic than of the Fire Flower going up instead of down and is slower trapping enemies so it doubles their points
But also maybe a straight shoot power-up like a Electricity power-up of of any other kind, or in this case a poison one as i thought