Euler's Formula appears in the Animation vs. Math from Alan Becker, despite being just a letter "e" with a "i" and a pi on top, it can still fight, with a "1" sword with a minus on top of a number as a handle, it can also turn into "4", "2"... any numbers. It can also create a behemoth "Aleph null" with an integral as a spear and shield at the same time(?) and a Taylor's Expansion cannon in the left, it can also clone itself.