some more variations:

# no need to join
perl -0x25 -e '$_{$.}=$_ while<>; print %_'

# dumps one random cookie (not just shuffling):
perl -0x25 -e '$_{$.}=$_ while<>; print ((%_)[$.==$.])'

# and this but slicing it
perl -0x25 -e '@_{<>}=1; print ((%_)[$.-$.]);'

# not sure but this works too (re: looks like slice key is created aft
+er slurping)
perl -0x25 -e '@_{1..$.}=<>; print %_;'
[download]

p.s. I did not know about -0x25, thanks