What is the name of the tiny male cells that fertilize the female egg?
Spermatozoon (plural: Spermatozoa)
Here is a diagram of a human spermatozoon with different parts illustrated :
Spermatozoa are male reproductive cells. They are around 60 micrometer long and are divided into head, neck, mid-piece, tail and end piece.
Head contains nucleus. Mid piece has mitochondria which provide energy for its motion. With the tail it swims to reach the egg to fertilize.