He is!
List of career achievements by Eddy Merckx - Wikipedia
In his best year he won 45% of all the races he entered (hence the cannibal nomer), which is very very hard, because the more well known you get the less other cyclists will cooperate with you, so you are basically racing against all the others.
In his first tour the france in his early twenties he won all the jerseys, he won al the monuments multiple times, the world speed record was not beaten for years... the fact that his wiki page mentions mostly the people who were able to beat him from time to time, tells more about him than his competitors... Yes I'm a fan ;-) And living in Italy, most italians are too (they are bike crazy).