So, I want to use this sprite and change its tilemaps, but I don't know anything about tile numbers. Is there a tool or something that allows me to see what numbers correspond to which tiles in SMW's gfx?
You can directly change the tilemap in the .asm file itself. Look for a table with the word 'tile' in it, which should contain all the necessary tiles.
However, in this case, there is no table. Instead, there's a define with the word 'tile' in it. Change that.
My Mode 0 guide.
My Discord server. It has a lot of archived ASM stuff, so check that out!