個

This keyword gave me trouble, I could write the kanji from memory but could not remember the keyword the other way around. In such case the dictionary definition can be helpful : "Middle English, single, indivisible". Here we have Mr. T. who is so hardened (all the body workout he's had) that he became in-dividual, that is, in-divisible. "I pity da foo who can be divided into smaller units."

Source: Kanji Koohii community