Fire Rocket
From TheKolWiki
Fire Rocket Type: CombatMP Cost: 0 usable once per combat

Source:  Great Wolf's rocket launcher 
Price:  N/A 
Class:  N/A 
Level:  N/A 
Effect:  Does X damage; causes Y damage to self. 
When Used: 
You fire a giant explosive rocket at [it / the ground in the middle of them], dealing X giant explosive damage. Unfortunately, the rocket part of the rocket burned your face pretty badly on its way out...

Notes
 X is equal to between 40% and 50% of your buffed moxie, with a group multiplier. Every possible value between 40% and 50% is possible, and the limit and maximum is floored.
 Y is equal to ⌊0.3*maxHealth⌋^{?} altered by Hot Resistance as expected.
 The group multiplier is ⌊(size + 1) / 2⌋^{?}. The multiplier is applied after the base damage is calculated, so a x2 multiplier would mean you always get an even amount of damage.
 If your moxie is low enough (1 or 2, buffed), you can deal no damage with this skill, X being replaced by "no". You still take damage as usual, and it counts as its use for the combat.