|Sell Creep Price:||3|
|An extremely powerful ricochet rifle.
Cobbled together from the compatible parts of the RUBE-ADYNE and its prototype, this makeshift gun provides maximum lethality in one convenient package.
- This gun is not needed for completion. You can unlock the Finished Gun without having this gun's Ammonomicon entry filled.
- Since this gun has no quality, the Resourceful Rat won't give anything in return for it if you trade it with him using the Ring of the Resourceful Rat.
- Rubenstein's Monster is peculiarly in the SHITTY gun class despite being quite powerful.
- Since Rubenstein's Monster is excluded from the normal loot pool, this has no effect on the player's likelihood to obtain the gun, but it will still reduce the chance of finding other SHITTY class weapons in future by an additional 90%.
- This synergy makes an appearance in the animated trailer for Advanced Gungeons and Draguns - specifically, being the only demonstration of a synergy.
- The fact that the RUBE-ADYNE Prototype and MK.II must be combined together to make a laser rifle is a possible reference to the dual-wield zap guns and the wave gun from Call of Duty: Black Ops' zombies mode, due to the zap guns being two laser pistols that combine together to form the wave gun.
- Its appearance in the aforementioned trailer reinforces this, with the two weapons being connected end-to-end much like the zap guns do to form the wave gun.
- The name of this synergy is a mix of “Frankenstein’s Monster” and “RUBE-ADYNE”.
- This is the only gun obtainable in normal play with no quality to not be a starter gun.