While tracking down a bug by yet another VCF parsing/filtering script, I realized that trimming a VCF is quite tedious and prone to shaving the actual bug while doing so while preparing the test case.

Does anybody know of a VCF randomizer/anonymizer/fuzzer that would allow me to share (cancer) sensitive VCF files publicly while keeping as much structure and problematic characters in the file? Also ideally with options to trim down the file by configurable factors as well if it's too big?