In Phantasy Star Online rag rappies are most likely named after the planet Ragol, al rappies are most likely named after the Algol system and the nab rappies in Phantasy Star Online 2 are most likely named after the planet Naberius.
Though they appear on Ragol, al rappies are the non-seasonal rare version of rag rappies in PSO, while in Phantasy Star Universe and PSO2 the non-seasonal rare rappy variant is simply called "Rappy" and appear on every planet, suggesting that al rappies are rare because they somehow traveled from the Algol system from the classic Phantasy Star games, though they are still considered to be native enemies, while the rare rappies in PSO2 are part of the "another" enemy group.
(There's really no solid evidence suggesting that Algol is or isn't the actual origin of Al Rappies so I'm tagging this trivia as a theory)
Evidence:
http://phantasystar.wikia.com/wiki/Rappy
http://phantasystar.wikia.com/wiki/Al_Rappy
http://pso2.cirnopedia.info/enemy_2.php#nav
Edit:
This is from an unoffical translation bit it should be accurate.
http://www.mediafire.com/convkey/e829/3v...zd6mzg.jpg (really, rag rappies being native to Ragol and Nab Rappies being native to Naberius is basic knowlage for these games).
http://www.mediafire.com/convkey/245e/av...lmqdzg.jpg
Though they appear on Ragol, al rappies are the non-seasonal rare version of rag rappies in PSO, while in Phantasy Star Universe and PSO2 the non-seasonal rare rappy variant is simply called "Rappy" and appear on every planet, suggesting that al rappies are rare because they somehow traveled from the Algol system from the classic Phantasy Star games, though they are still considered to be native enemies, while the rare rappies in PSO2 are part of the "another" enemy group.
(There's really no solid evidence suggesting that Algol is or isn't the actual origin of Al Rappies so I'm tagging this trivia as a theory)
Evidence:
http://phantasystar.wikia.com/wiki/Rappy
http://phantasystar.wikia.com/wiki/Al_Rappy
http://pso2.cirnopedia.info/enemy_2.php#nav
Edit:
This is from an unoffical translation bit it should be accurate.
http://www.mediafire.com/convkey/e829/3v...zd6mzg.jpg (really, rag rappies being native to Ragol and Nab Rappies being native to Naberius is basic knowlage for these games).
http://www.mediafire.com/convkey/245e/av...lmqdzg.jpg