What are your favorite random encounter enemies of any of the classic Phantasy Star games?
My answer is probably pretty typical, but my favorite out of all the games are the Fiend/Thoul types, with the different colored capes with hoods and their skeleton-like arms and hands. In PSII Fiends occasionally escape megid, which makes them particularly cool, and in PSIV the Thoul/Lars/etc. know a lot of techs and just seem more developed as magical enemies. Plus they're kind of scary looking (scarier in PSII, but that was just the style of animation in that game).
Other than that, in PSI I like the Amundsen/Frostmen. They were unique looking and weren't carried over into the other games for some reason. Owl Bears/etc. are classic, too. I like them because they remind me of 1960s Filmore poster art work.
In PSII I really liked the mechanical enemies. Attmech/etc. had really cool attacks. They didn't look that impressive, but then they'd stand up and fire missiles at you. Head Rots were creepy and very hard at that stage in the game, and the regenerating Slugmess was a pain in the butt (Blastoids could also regenerate, but they had a really weak attack and were never a problem for me). I remember the first time getting to Zema and having little to no cash for new weapons, but decided to try Roron, anyway. How hard could it be? Hahahaha. Slugmesses killed me before I reached the end of the peninsula.
In PSIII, ah, well... Lobowings/etc. confused me at first. I thought they were snails with some sort of animal head for a foot, then realized I was looking at them wrong! They're one of my favorites because they're so bizarre-looking. The Doomflies were interesting. If I didn't attack first, they would poison me almost without fail, and since they're on the back row I almost always got poisoned. Stupid flies. Floppers are highly improbable enemies, but I like them in a nostalgic way now.
PSIV had a lot of great enemies; the ones that could merge and create newer, stronger enemies were quite impressive. I also liked the various moles. The way they'd come up and *SLAP!* your crew was hilarious. I didn't really like the mechanical enemies in PSIV, but almost all the magical enemies were well done. Dimension Worms were scary stuff, huh? Weapons weren't effective on them at all. Radhins were great because they'd spend the first round casting all these defense spells and looking rather intimidating, but then the heroes would just be like, "yeah, whatever" and slice and dice them, anyway. Marauders were a great carry-over from PSI.