I had a marbled goby that ate M+Ms, lol
As to collectng toxins,
1) becareful or you will die
2) research current laws or you WILL end up in jail (times have changed)
3) learn how to make glass lab ware as sealed glass vails are the best for safe storage and display
4) document acquisitions..., include date, source, price, LD50, etc.
5) refer to #1..., in the case of ricin or botulin toxin accidently ingest a crystal smaller than a grain of salt can kill you. for things like nicotine even inhaling the fumes generated during distillation can make you very ill.