Go to
This Site, the navigation bars on the left side take you to the battlers and the faces to match.

@Oldman
The script with the monster ID is called:
Enemy Animated Battlers - It should be underneath the 5 core scripts for the side view battle system.
PS. If what you meant was how did I get THAT sprite then just do this...
1) Export the 'Monster' sprite sheet from the resource manger 'Character' section.
2) Edit the sheet so that only the 3x4 grid of the monster you want is shown.
3) Save 4 copies of the same image each with one of these names. (replace example with the name)
$Example
$Example_1
$Example_2
$Example_3
4) Import all these files back into the character section of the game.
5) Import just the first image into the character section of the resource manager.
And your done.

The '$' is needed!!