All other air units have an 'imgul' command to load their shadow images, which are just their normal GRP using the shadow method of drawing.

Carriers however do not use the imgul command, yet they have a shadow!

Also in decompiling *all* of the IScript.bin into IScript.txt, there are no references to image 113 which is the Carrier Shadow. I then ran a search in IScript.bin with a hex editor for single bytes with value 0x51 (113) and came up with only one result, which I think leads nowhere: "47 00 05 01 00 51 00 05 01 00"

What's going on!? Is the shadow for the Carrier hard-coded? Is it referenced in one of the DAT files or something?

I'd really like to get to the bottom of this, any insight would be appreciated!

The carrier uses the IceCC opcode "imgulnextid." From the opcode description: " * imgulnextid 0x3d - <x> <y> - displays an active image overlay at the shadow animation level at a specified offset position. The image overlay that will be displayed is the one that is after the current image overlay in images.dat."