When the Big Rex (npc-162) is defeated, it turns into the stomped Rex (npc-163), however it used a transition effect, which looks like this:
Secondly, when npc-163 spawns, it spawns from the head of npc-162 and drops to the ground. Npc-163 should spawn on the ground, to make it appear as though Rex has actually been squashed into the ground. The transition frame I mentioned before shows in between the death of npc-162 and the spawning of npc-163. This makes the change between the 2 sprites much more fluid, and a lot less weird.
The third thing was how Rex has a special death effect when swallowed by Yoshi. This is only used in SMA2 (GBA Super Mario World). You can see it here:
This is used as opposed to the regular sprite of npc-162. It is not used if Yoshi swallows npc-163.
The was a fourth fix, which was originally a Redigit error, by where when Rex is defeated, in Super Mario World, he falls off the screen in an upright position, as opposed to in SMBX where he flips upside down. That's not particularly a problem, considering we can fix that ourselves by rotating the sprite effect in Paint.NET, but maybe that could be fixed in future versions, as to appear more accurate.
