Advancing onward from 2e, let's take a look at 3e!
Monster Manual (3.0)
There are no monsters only core in this book, and never again.
However, there are plenty introduced here that were only core in 3e:
Aasimar
Achaierai
Allip
Animated object (generic)
Aranea
Arrowhawk
Assassin vine
Barghest...