The file copy command will cause the terminal to exit out if any of the two arguments provided is invalid. It wouldn't exit out if you provide 1 or 0 argument.
If I write "filecopy a b" while a and b are not real file/directory names, the terminal will exit out.

https://docs.python.org/3/library/cmd.html

The "end" and "kill" command are buggy, and if you put end or kill and a letter between a-y, it would destroy your computer. I tested this on my linux vm and it the vm blacked out and restarted. (I'm afraid to test this on my windows computer)
For example, type "end a" or "kill y" and enter