Not to be confused with SIXBONES.
The Bromalgamate is an Amalgamate of Sans and Papyrus. How they melted together varies on who drew it.
In the other AU, they melt through unknown means, but in the Good Ending of this AU, they form a sentient being, named Comic Papyrus.
In both AUs the Bromalgamate is quite horrifying. In the one with Comic Papyrus, the entire body is goop, and the two skelebros are seen holding hands. Their clothes are seen. In the other, it's much cleaner. Sans's pupils are gone, and his right eye socket is melting, obscuring his mouth. His arms hang down, one melted over next to Papyrus's left arm. His torso clips off behind Papyrus's scarf, then reappears next Papyrus's pelvis, covering Papyrus's waist with his own. His slippers melted, and the right one mixed with Papyrus's right boot. Papyrus has a melted face, and his right arm is melting. His left hand is permanently stuck to Sans's head. His right leg is more misformed than his left, and his nose-hole is seen melting.