In many cases a teratogen is a mutagen, that causes malformation as an embryo is developing. Some analogies for mutagens are in the link.
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.