This site has a huge library of single cycle wave forms for use in FL (and other synths that you can import wave forms) synths like Toxic Biohazard. You could literally spend years going through them all and they are all free. Enjoy.
http://www.adventurekid.se/akrt/waveforms/
They also have a library of strange IR files you can use with fruity convolver
Single Cycle Wave Forms from Adventure Kid
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