def files_target_count(target, *args):
    """
    Write a function that takes in a target character and files.
        Count the # of times the target character appears in all of the files.
        ** Not case sensitive.

    >>> files_target_count('e', 'files/file1.txt', 'files/file2.txt')
    5
    >>> files_target_count('\\n', 'files/file1.txt', 'files/file2.txt')
    10
    >>> files_target_count('E', 'files/file1.txt', 'files/file2.txt')
    5
    >>> files_target_count('', 'files/file1.txt', 'files/file2.txt')
    0
    >>> files_target_count('e', 'files/file1.txt', 'files/file2.txt',\
     'files/file3.txt', 'files/file4.txt')
    99
    >>> files_target_count('\\n', 'files/file2.txt', 'files/file4.txt',\
     'files/file3.txt')
    26
    """
    count = 0
    for files in args:
        with open(files, 'r') as f:
            for line in f:
                for char in line:
                    if target.lower() == char.lower():
                        count += 1
    return count