Someone who in a stealthlike performance drinks the milk, someone who is very Jedi when it is time for mass amounts of milk to be moved.
"MOM: Where the fuck did all the milk go?" SON: "I dont know I havent had any" all in the while he is smiling with complete accomplishment in his head, just like a true MILK-NINJA
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!