perl -le 'printf( "\\x%02x\\x%02x\n", unpack( "C2", pack("n", 12)))'
\x00\x0c
# Another way to say that . . .
perl -le 'printf( "\\x%02x\\x%02x\n", unpack( "C2", pack("S>", 12)))'
\x00\x0c