crafty
黠 centers on cleverness used in a sly or cunning way: being crafty, wily, or shrewd in a manipulative sense.
黠 combines 黑 (black) with 吉 (good luck), but the exact historical development is uncertain. It may have originally suggested a dark or hidden cleverness, though this is speculative.
The left side 黑 suggests something dark or hidden, and the right side 吉 looks like a clever person with a lucky scheme. Picture a crafty fox hiding in the shadows, using its wits for a sneaky advantage.
For カツ, imagine a crafty cat sneaking around: cat -> カツ, and the cat's sly movements match the kanji's meaning.