Board Thread:The Reference Desk/@comment-188432-20130505035914/@comment-188432-20130508011217

Red leech poison isn't really conjectural. Vastra says "it secreted a fatal poison". So, using common sense English, "it" means "red leech", and thus there's "red leech poison". is for when we're wholly creating a term not at all supported by the script.

It can have its own page, as we have clear visual evidence that it is a separate thing to the red leech itself. If we can have cattle and milk, or humans and blood, or bees and honey, we can have red leech and red leech poison.