Similar Kanji: 猫 (Cat) and 描 (Draw)
As I practiced writing out reading sections of my Japanese textbook, I thought I was writing out the right kanji for cat (猫 – ねこ / neko). Instead I made a slight mistake on the left radical and wrote 描, which is the kanji character for draw. The difference between the two left radicals is very slight. Both consist of three strokes, one long vertical stroke and two horizontal strokes.
After spending a couple minutes thinking how I arrived at this error, a very clear and obvious association popped up. The left radical 犭 on the kanji for cat is called けものへん (kemonohen), or just ケモノ. The English radical meaning translates to dog.
The Japanese definition though is a bit different, but gets the similar meaning across. The word kemono (also said as kedamono) means beast. There is an actual kanji for this. It is 獣. On the right side of the kanji you have the kanji for dog, which I think they used for the radical we know now know as けものへん. So if you think of a cat as an animal, you could imagine it as being some beast, say, a ferocious lion or tiger.
描 on the other hand has the radical for hand, 手. You simply have to remember that you draw with your hand.
Here is a very simple sentence that helped me remember these two:
neko wo egaku
Draw a cat
 It has been brought to my attention that kedamono can be used as a slang when a guy tries to entice his girlfriend in a romantic setting.
けだものになっちゃおうか (Kedamono ni nacchaouka? – Shall I bring out the beast in me?)