Answer
"The Tank" is the befitting nickname for Belgian cyclist Freddy Maertens, who earned the moniker due to his aggressive and determined riding style that powered him to numerous victories in the 1970s. While "Mister 60 Percent" emphasizes Maertens' dominance in winning an impressive 60 percent of the races he entered, "Fonske" and "Freddy the Cannon" are affectionate nicknames that highlight his popularity and achievements in the cycling world.