Nicotine I don't think was used to much by the ninja but it is worth mentioning for sure, if prepared in a high enough dose it would cause certain death. A lethal dose of nicotine is anywhere from 40 - 60mg depending on the person, the average cigarette's tobacco alone contains about 20mg.
Preperation for pure Nicotine:

           1. Buy tobacco [cheap cigarettes or a pouch of pipe tobacco]                   

           2. put tobacco in a jar [pyrex heatable container]

           3. add an equal amount of rubbing or distilled alcohol preferably over 100 proof.

           4. simmer and stir until it looks like coca-cola colored.

           5. strain tobacco mixture out into another pyrex dish.

                                                                6. if you want it to become more potent, keep using the same liquid for about 3 batches.

                                                                7. After the potency you want is acheived, strain and keep in another dish.

                                                                8. After washing your heatable container, boil off all the excess liquid until a semi thick syrup remains.

                                                                9. that's pure nicotine.

                                                              10.note: tasteless in coffee and other heavy beverages. 2 drops, maybe 3 will kill someone.