use Net::FTP::Common;

...
# Get all .png files (and .PNG, .Png, etc)
for ($object->grep(Grep => qr/\.png$/i)) {
    $object->get(File => $_);
}
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Note: this uses a regex, not a glob! And this snippet would also download files with names ending in ".png\n".

2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$
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