0:01.4 - 0:05.8 John Pomeroy (lava monster), Ted Kierscey (effects), Artist Unknown (Sprite)
0:05.9 - 0:21.3 Sandro Cluezo (Sprite), John Pomeroy (lava monster), Ted Kierscey (effects)

Sandro Cluezo includes 0:05.9 to 0:17.5 in two demo reels, but always stops on frame 419. I don't know why he wouldn't have animated the sprite for the rest of the cut, but it's possible Pomeroy or someone else did

Last two cuts look like Pomeroy with some possible Kierscey touches, but I haven’t found confirmation yet

Anthony DeRosa is definitely here in some capacity as Lead Sprite Animator as well, so I'll tag presumed.

https://vimeo.com/41973740
https://www.youtube.com/watch?si=G4h8jwtkg-mcNe_C&v=2OSokNLqyAI
https://www.instagram.com/johnpomeroyart/p/CpmfqMeuTTt/
https://www.instagram.com/johnpomeroyart/p/CIAO-51j2Ae/