These Species can be obtained during the Second Collaboration event if you fulfill "Special Conditions" (See http://www.playonline.com/pcd/topics...18/detail.html)
The Special Conditions are to obtain the Cap, Shield, and Earring for both Metal and She Slimes, as well as a Slime Fetish (You'll need it later, if you didn't get in the last event):
Slime Fetish: 10 Slime Coins
Metal Slime Cap: 30 slime coins
She Slime Cap: 30 slime coins
Metal Slime Shield: 20 slime coins
She Slime Shiled: 20 slime coins
Metal Slime Earring: 15 slime coins
She Slime Earring: 15 slime coins
So the total amount of slime coins you'll need to farm are about 140 coins. Once you obtain all of the items, then there will be cut-scene where the NPC awards you the Metal Slime and She-Slime spirits.
In the Feretory, you'll need to trade the spirits to Suibhne to earn the species, but it seems that he will not accept the trades unless you are possessing the Blue Slime (tried trading the metal slime as the red slime, but it didn't work until I changed back to blue).
Blue Slime: WAR/WAR
Red Slime: WAR/WAR
Grey Slime: BLM/WAR (Very high evasion and defense, but laughably small hp pool)