Sorry metroixer.
I wouldn’t have thought about it myself, but confusing red and green does ring certain alarm bells. It’s not something you’d want to do while holding hopes of becoming, say, a pilot.
If by
Calvary you mean the hill where Jesus was crucified, then no. If you mean a
carvery, then I don’t imagine Mudokons having such a restaurant, but I don’t know if they’d eat Scrab or not. They are considered holy creatures, but then Earth’s native cultures don’t necessarily hold sactity and edibility to be mutually exclusive. If you mean
cavalry, then it’s hard to imagine anything taming a Scrab, though I remember it as being a staple of fan fiction that Mudokons somehow managed to cling to their backs and ride them about. Maybe one day we’ll see characters riding Scrabs.
My interpretation was that they’re restraining the Scrab so that it doesn’t go on a rampage and kill them all. They’ll release it somewhere (if they don’t use Scrabs as a natural resource).