use Data::Dumper;
my @bigarray = (
[ "123*jeff", "tortoise", "qwerty" ],
[ "456*john", "parrot", "azerty" ],
[ "789*jane", "budgie", "abcdef" ],
);
print Dumper \@bigarray; # before
...
print Dumper \@bigarray; # after
####
splice @$_, 0, 1, split /\*/, $_->[0] for @bigarray;
##
##
foreach my $arr ( @bigarray ){
my $item = shift @$arr;
unshift @$arr, split /\*/, $item;
}