summoning the dragon
This defines when someone uses the bathroom.
I would've made in time if I wasn't summoning the dragon!
Summon the Bone Dragon
To suffer an uncontrollable erection that tears through one's pantaloons. Only a select few suffer from this condition, which occurs each year by the light of the hunter's moon.
Though he may walk amongst us as a normal man, come the autumnal equinox he will summon the bone dragon, thereby revealing himself.
Summoning the mud dragon
Colloquial term for taking a dump.
I really have to pop, so I will be summoning the mud dragon.