use 5.012;
use String::Diff;
use Data::Dumper;

my @strings = (
    "This is the wild cat",
    "Thsi is the widl cat",
);

my $diff = String::Diff::diff_merge(
    @strings,
        remove_open => "<mismatch>\x08",
        remove_close => "\x08",
        append_open => '',
        append_close => '</mismatch>',
);
$diff =~ s/\x08.+?\x08//g;

say $diff;

__END__

Th<mismatch>si</mismatch> is the wi<mismatch>dl</mismatch> cat