Combination Swapfell Sans is a fusion of the 2 different variations of Swapfell Sans. Combo Swapfell Sans was made by TheNitroFlamer.
As one can guess, Combo Swapfell Sans has a design similar to both versions of Swapfell Sans. They are a short skeleton with sharp teeth and cracks running down to their eyes, with their left eye being dark crimson Triforce while their right eye is a red and grey Triforce. Their battle body features a dark grey chest-plate with gold sleeve rings and a pale gold Starman logo with the triangle being an upside down Triforce. Under their chest-plate, they wear a gold T-shirt and black pants with pal gold stripes, held up with a gold belt. They also wear dark crimson gloves, boots and a torn scarf, which protrudes up in a torn wing shape and hangs below their waist.
Combo Swapfell Sans is very mean, serious and sassy, as well as narcissistic, often praising themselves as the greatest monster of all time. They are also very cruel and violent, enjoying the torture of anyone, especially the two versions of Swapfell Papyrus. They are also pretty irritable, easily getting pissed when things don't go their way, and they are very energetic.
- When they speak, they use two voices overlaid, with each representing one of the versions of Swapfell Sans.