Itchy, Scratchy and weapon sprites are uncompressed in ROM.
Enemies needed ripped from VRAM.

Level maps are stored in RAM starting at address 2000; each tile is a 2-byte value, the first byte its palette, the second its graphic. Graphics usually increase in increments of 2.
In the main levels, rewriting a tile will change it immediately, making it very easy to run a macro to grab the tileset.
In boss levels, a tile only 'refreshes' once it is off-screen.

You can visualise the map when opening the savestate in TiledGGD by setting the canvas to 384px 16bpp.
(the bytes in a savestate are the wrong way round compared to RAM, so a Python script to swap their positions before exporting to whatever mapping tool you use is recommended)
(levels and boss stages have different tile arrangements, so you can't reuse the former's efforts for the latter)
Animated tiles are stored after the map data which is very handy!

Unique sprites from the unreleased SEGA Genesis version were included, recoloured to match SNES palettes. Scratchy in particular has reduced colour depth.






	ROM DATA (SNES)
20000	palettes (stages?)
27A00	palettes
D0000	palettes (itchy, scratchy, weapons)

D8000	16bpp 16px, level chunks...?

bizhawk savestate has level data at FE46 (384px linear, 16bpp)


	RAM ADDRESSES (SNES)
00D6	camera x-pos
(there are seemingly two addresses for camera y-pos but it's not as cooperative)

0210	level warp (shows title card but wrong level)
0229	LEVEL WARP (01~07 are levels, 08~0E are bosses)

022B	itchy health
022E	kill itchy instantly
0230	itchy invincibility

0231	scratchy health

0238	timer minutes
0239	timer seconds

023A	lives
023C	projectiles

07CC	itchy weapon
	0 mallet
	1 oar
	2 dinosaur bone
	3 flail
	4 cinder block
	5 hammer
	6 frying pan
	7 shovel
	8 executioner's axe
	9 tomahawk
	10 fire axe
	11 van de graaff generator
	12 chainsaw
	13 swordfish
	14 cutlass
	15 hot rivet gun
	16 antique pistol
	17 machine musket
	18 harpoon gun
	19 bazooka
	20 cannon
	21 flamethrower
	22 gatling gun
	23 flaming bow and arrows
	24 bomb
	25 boomerang
	26 stone
	27 cannonball (small)
	28 exploding rocks
	29 gas pellet
	30 starfish
	31 sheriff stars
	32 dynamite
	33 burning torch
	34 bone (lvl1)
	35 stone block (lvl2)
	36 cannonball (lvl3)
	37 starfish (lvl4)
	38 cactus (lvl5)
	39 cinder block (lvl6)
	40 wrench (lvl7)
	41	CRASH

0804	scratchy weapon

0E8C	itchy x-pos
0E91	itchy y-pos

0E9A	itchy animation frame
0E9C	itchy animation
0E9D	itchy animation

0FBF	scratchy x-pos
0FC3	scratchy y-pos

0FCC	scratchy animation frame

1A86	weapon icon graphic swap

2000+	level tile data (increments of 300 in hex per line)





	RAM ADDRESSES (SEGA)
0503	LEVEL WARP (level, boss, level, boss)
062B	scratchy health
172F	weapon icon graphic swap

ta to Zachary1021 for a quick rundown of differences in the Genesis version
https://gamefaqs.gamespot.com/genesis/582930-the-itchy-and-scratchy-game/faqs/81753/snes-and-sega-genesis-differences