Mr. P is a large, sentient, phallic creature found within the Mechanical Mine, guarding the last pump Valor needs to activate to drain the lower levels of the mine. When Valor hits him, he splits into 2 and then 4 smaller versions of himself before being killed.
... (@[email protected])
... <(_ _)>
Monolith of Minds partnered with German company Dil Do It to 3D print a Mr. P dildo, which was subsequently given away to a fan.
According to Mr. Kiepchen, Mr. P's full name is "Mr. Penetrator."
Boss Fight Guide: Mr. P
Mr. P will simply try to run into you, and will fall over if he hits a wall instead. Once he falls over, hit him before he gets back up, and repeat until he splits. Repeat this process until all 4 smaller copies are killed.