Cyclopamine - The Purple People Eater's mom must have had a taste for it

• steroidal alkaloid actualized by Veratrum californicum (corn lily or vetch weed), a plant native to the subalpine meadows of the western US
• teratogenic, meaning that it causes congenital (birth) defects, specifically cyclopia
• cyclopia (AKA cyclocephaly or synophthalmia) is severe facial defect that results from a type of holoprosencephaly (the failure of the forebrain to divide into distinct hemispheres) that messes up the development of the face such that the two orbits merge into a single cavity, containing one eye, in the middle of the face in place of a nose
• gets its name from the Cyclopes of Greek mythology, a race of one-eyed giants that snacked on people
• inhibits the Hedgehog (Hh) signaling pathway, which is involved in the regulation of prenatal development
  
• cyclopamine is currently being investigated as a possible anticancer drug, since an overactive Hh pathway can contribute to the development of many different varieties of cancer
  
• the corn lily closely resembles hellebore, an herb reportedly used by some pregnant women as 'natural' means of treating morning sickness and cramps, which has on occasion led to them eating the wrong plant and having a deformed kid
• jervine is a related (just add a ketone group) teratogenic alkaloid found in the corn lily that also causes cyclopia
  

Incardona JP et al. The teratogenic Veratrum alkaloid cyclopamine inhibits sonic hedgehog signal transduction. Development. 1998 Sep;125(18):3553-62.
http://hedgehog.sfsu.edu/overview.html