This character is based off of Grillby but is not the Grillby of any AU, essentially making him an OC.

This form of Grillby was made by Dr. Terminal Gaster in his lab. The purpose of his creation was to see if Dr. Terminal Gaster could make a living monster from the fusion of souls. Gamby has a soul from 3 different fused souls: Classic! Grillby, UnderFell Gaster, and UnderSwap Sans. His body is made from fire magic and nuclear waste, so he must stay in a glass box at all times.

The only one who is allowed near him without a radiation suit is Outertesty, another test subject of Dr. Terminal's.

please go to ask-dr-terminal-gaster to learn more



Gamby MC Radioactive looks extremely similar to Grillby. The only difference is his color scheme. He now has a predominately blue flame and green suit/bow-tie.


He's quite cheery most the time, although he doesn't talk much, but if something wakes him up, he's pissed and screeches loudly, although not enough to shatter his glass box.