The Live Wire

This guy is currently screwing around with it

Basically it lets you take giant eggs into any level. You can use this to instantly kill Marching Milde. As a consequence, you can sometimes use it to get Yoshi stoned in any level. If you use this and jump into a goal, it frequently softlocks, because the other Yoshi shows up stoned and often fails to catch Baby Mario, leading him to go into a bubble and start crying endlessly while the Yoshi slides around. Like, who finds this stuff?