The Oven-o-Tron is a device that is used to heat up objects, very similar to a real-life oven.
The Oven-o-Tron appears to be a dark grey rounded cube. It has a sign saying "OVEN-O-TRON" above it. There is no hatch or oven door of any sort.
The Oven-o-Tron 2000 boasts a larger, more rigid shape, no longer being cube-like. The sign is replaced with text directly imposed on the side of the oven. There is also a yellow and orange quadrilateral design on the top of the oven. The Oven-o-Tron also has a green button and progress bar on its side, as well.
The Oven-o-Tron first appeared in "Sweet Tooth", where it was used to bake cakes.
The Oven-o-Tron's latest appearance was in "Zeeky Boogy Doog", located in Golf Ball's Underground Factory, when Team No-Name used the Oven-o-Tron (now the Oven-o-Tron 2000) to heat up the Dream Sauce, converting it into Dream Island (which was later blown up by W.O.A.H. Bunch).