$5FC0 may be the R2 Worm snake ?
$7144 might just be the R2 AntLion or R2 BurroBot, as both seem to relate to being underground, although the AntLion seems to be a more likely a candidate. (I don't think the BurroBot was meant to go down deeper, but who knows lol ) but yeah the chunk drawing in the foreground could be rocks being displaced by the badnik as it moves deeper.
any way to get the AntLion sprite from below into the game and than test it out ?
I kind of doubt it is any of them; I think that these may be used on other SCD levels, but I haven't disassembled them all to test it out.
$5FC0 is completely stationary, apart from being animated; but since its animation data is missing, I can't be sure about anything. I only know it is a badnik of some sort because its collision flags are set to 6, meaning (1) it can hurt Sonic, (2) it can be destroyed by jumping on it, releasing a flower and (3) it is 6 by 6 in hitbox.
$7144 is not a badnik of any kind; here is a better description: it displays one of two sprite frames: both are 4 tiles high and 24 tiles wide (192 pixels), using 6 4x4 sprite pieces. All sprite pieces are identical, and they refer to either the 16 tiles at $3BA for frame 0, or the 16 tiles at $3CA for frame 1. Each frame is displayed for 5 frames before changing. The object's width setting is incorrectly set to 16 pixels, though, so it will vanish quickly if it gets off-screen. It will descend 4 pixels each frame until it has "fallen" $180 pixels. Until then, it will also draw a row of 12 16x16 blocks to plane A from the level layout centered at its current X position whenever its Y position is at a multiple of 16 pixels. It will only draw to non-empty blocks (not ID 0), and it will overwrite the corresponding chunk entry with $2002 (block $10, palette line 1; the corresponding chunk will start using $2002 instead of what was there before) and will try to write the corresponding tile through to VRAM (but fails). When the screen is refreshed (e.g., when you move away then come back) it will have the updated tiles.
In R11A the sprites are mosquis and the blocks are partially transparent grass tile.
$7144 is only on the Palmtree levels.
and for some of the listed code, are there any screens and video showing any of that stuff off ?
What about the 510 Beta, has PPZ been fully explored there as well?
Except for qyuu's data dump, not public, not as far as I know. My R11A work is probably closest as I posted links to it on IRC, and have been meaning to finish splitting it and make scripts to help automate disassembling the other zones, but haven't had time for it.
This is all very interesting! I really appreciate you sharing some of your discoveries! I'd really like to say keep up the good work and maybe sometime when you get far enough, or when you have some time, I think everyone would love to see a topic or wiki or something dedicated to what else you uncover! ( even if its Work in progress) Sonic CD is my favorite Sonic game when it comes to hidden discoveries and unsolved mysteries. I must have more!
I still think that the snake worm badnik would fit the bill nicely for the $5FC0 you found, as it seems like it'd be a badnik which does not move. but yeah, we may never know. Also if you look into the beta dump, you may get some more clues and info related to R11A? If the beta has an R11A that is.