The letter K comes from the Greek letter Κ (kappa), which was taken from the Phoenician  kap, the symbol for an open hand.

This, in turn came Egypt from the hieroglyph for hand. The first people to make an alphabet made it a K because their word for hand started with that sound.

In the earliest Latin inscriptions, the letters C, K and Q were all used to represent the sounds /k/ and /g/ (which were not differentiated in writing).

the forth letter K was from paleo-Hebrew:

The last letter K was from Greek: