Tsar Bomba

Tsar Bomba (also known as the floating bomb glitch) is a glitch that allows a bomb to be stalled in midair indefinitely during the Hariet fights in Bowser's Kingdom and Dark Side. The glitch is caused when Mario knocks both of Hariet's bombs back at her at around the same time; after the first bomb stuns her, the second will stall at the end of its trajectory and float indefinitely. The floating bomb can then later be used to stun Hariet or cancel her hovering attack even before she has released any bombs during that phase, which can speed up those cycles.