The anatomically-correct tag was recently created, which I noticed when all the questions in that series were edited to add it. Do we need this tag? The questions also have the appropriate other tags like creature-design. anatomically-correct feels like a meta tag to me. If exactly the same question were asked by somebody who didn't know about or intend to participate in the series, would the question get the tag? What value does this tag add?
As they would say on Stack Overflow: BURNINATE IT!
The tag is definitely, as 2012rcampion states, an intersection of creature-design and reality-check.
Furthermore, every question tagged with it already starts with "Anatomically correct"; to me, it almost feels like the tag is used solely to categorize questions starting with that title, which is totally wrong.