The hitch hiker responded, stating, "my mission in life is to kill men with small penises." He then then told the friends that he would spare them if the collective length of their penises was 18 inches. The hitch-hiker then took a tape measure out of his pocket and told the fishermen to drop their pants.
He measured the first man, 8 inches. He measured the second, 7 inches and then measured the third, three inches. He then grimaced and said, "ok you guys, I'm a man of my word, you've made 18 inches so I'll spare your lives." He then asked to be let out of the car and disappeared into the scenery. The fishermen drove off feeling relieved. A bit further along the road the first fisherman said, "boy am I glad that I had 8 inches." The second fisherman responded and said, "thank the Lord that I was given 7 inches." The third fisherman paused for a moment, then said, "I'm really glad I had an erection."