. . . represents humanity in G-d's image.
Notice the "thorn" at the upper-right corner of this letter.
The letter Tzadik Kefufa consists of pieces from 2 different letters. There is a Nun Kefufa, which is more curved than it normally is, and has a bigger bottom base than normal. There is also a Yud, which is resting on the back of the Nun part. The left head should have 3 Tagin on it, like a regular Zayin. The overall size should be 3X3 kulmusim. The heads should not touch one another at all.