On recent-ish Linux systems, `ls` prints names with weird characters using the shell's quoting syntax. If that `'.env'$'\r'` is what `ls` gives, the name of the file is `.env<CR>`, where `<CR>` is the carriage-return character. You could get that if you had a shell script with Windows line-endings that ran e.g. `whatever > .env`.

The good thing here is that the output of `ls` there is directly usable as input to the shell. Well, to Bash, ksh, and zsh at least, not a standard POSIX sh, like Debian/Ubuntu's `/bin/sh`, Dash.

So try with just 

```
rm -f '.env'$'\r'
```

Of course `rm -f .env?` should also work to remove anything named `.env` plus any one character.

Now, of course it's also possible that the filename is literally that, what with the single quotes and backslashes. But that's more difficult to achieve by accident. Even so, `rm -f *.env*` should work to delete anything with `.env` in the name.