The jacket is a simple labcoat that was dyed with Rit PolyDye. The dye itself was a black colour, but it came out as a gray which I feel was a happy accident as I actuallyi perfer that colour. The gloves were coloured in with a black Sharpie and the rest of the pieces were just extra clothes or bits of fabric I had sitting around. The yellow flowers are actually leftovers from Chara; I was going to make a flower crown for him but didn't like the look of it, so I used the folowers on Gaster's arm instead.
It's a very fun costume to wear around as I usually bring my tablet with me to "talk" to other people. These are all just premade image files in the Wingdings font.
I really must love Undertale because it was the first video game that I cosplayed more than one character from.
The costume itself is fairly simple. The head is 3D printed and LED lights are inserted into the eyes. A friend of mine actually printed the head and did the lighting for me. I've always said that if anyone ever makes me something, that I will wear it, regardless of what it is... thankfully this is a character that I really wanted to dress up as, instead of, say, seeing me in a Sailor Mercury outfit.