This works for me:

use strict;
use warnings;
use Data::Dumper;
my $line = 'One animal="ap3!" and another one fish="s4lm%%on" 
can all be eaten. (So can the bird="sparr0w!$$")';

my %hash;
while ($line =~ m/\b(\w+)="([^"]*)"/g) {
    $hash{$1} = $2;
}
print Dumper \%hash;
__END__
$VAR1 = {
          'animal' => 'ap3!',
          'bird' => 'sparr0w!$$',
          'fish' => 's4lm%%on'
        };
[download]

\w includes digits and underscores, no need to list them separately.