Mr. Crazypants keeps dangerous items like dynamite and TNT in his pockets. He warns his friend that they are like "YaLuLuLu", which is either dynamite or TNT, and threatens to set it off if his friend doesn't run away within 10 seconds. His friend refuses to run, so Mr. Crazypants sets off the explosive, though onomatopoeically rather than with detail about an explosion.