Thanks, guys!
These have greatly helped inspire me. It helps greatly to know what I'm looking for & where.
@Brian: Yeah, but I think the FF games mostly had Lamia, half-woman half-snake, enemies; they might have other snake enemies, too, but that's the only kind I remember. The FF games sure do have other epic enemies, though!
@Fausch: I didn't find that snake, but what I did find, when searching for "cobra" on Spriter's Resource, was a smaller cobra enemy from a DS game called "Children of Mana". It fits 2x2 tiles, but most of the sprites are 24 pixels tall (whereas 2x2 tiles are 32x32 pixels). Still, it's something I can work with!
And I don't what that game is you have pictured, but that looks wicked!
Looks like a totally rad game to play! I'm guessing it's probably an arcade game, by the looks of it; but, then again, I guess there are console games that also say "Push button" for player 2 to join.
@Theryan: I took a look at those games (except for Mother 2 & 3; out of the three, I only looked at Mother 1) on Spriter's Resource & the web, and saw the snakes you were talking about. I hadn't seen the Harry Potter game before either, but they had Basilisk sprites!
I've been reminded of the usefulness of having a segmented body for a big enemy like this. I haven't fully decided how I'm going to proceed (meaning which size I'll choose), but these have definitely lead me in the right direction. Thanks, guys! 
BTW, in case anyone else is looking for something like this, I also found Snake Jafar from the SNES Aladdin game and the snake enemies from Chrono Trigger, Gnawer & Gnasher. Of course, Aladdin's a side-scroller game so those sprites are not as useful in this regards. Regarding Gnawer & Gnasher, for some reason Spriter's Resource didn't have the sprites for them facing left & right; only up & down. (I've played Chrono Trigger before and I know they can move in all four directions. Oh well.)