Metroid Fusion - Unused Enemies (Kago, BOX Missile)
The Kago does not actually have code to spawn the insects. I had to modify the code myself, so we can't be sure how the developers intended the insects to be spawned. Unlike other unused enemies, the behavior for the insects themselves seems to be fully functional. The insect spawning behavior may have been removed for a number of reasons. It might be related to the fact that the Kago can mutate and be frozen. It could also be to avoid having too many sprites.
There is unused code for a missile along with the other BOX related code. As it turns out, this is almost an exact copy of the missile used in the second BOX fight. Therefore, my guess is that the first BOX they developed was able to fire missiles, then they copied all of the code when they decided to have a second BOX fight. However, the missile graphics were removed from the first BOX fight, so I put them back in. Otherwise they would look like a glitchy mess. There's also no code for firing missiles, so I changed the projectile it normally fires to a missile.