There is one respect where the mormons are like Catholics however, both have an earthly leader who claims infallabilty, and therefore, the right to determine which books should be contained within the canon (list) of scripture (the bible), for most protestants the list of books in the bible is just someone's opinion, and that person could be wrong! (He left out Harry Potter 4
There is a significant difference. In the Catholic faith, the Holy Father's infallibility is only on matters of faith and morals, and only when he expresses the beliefs of all of the Catholic faithful as expressed through the bishops, and only when his teaching is consistent with previous Catholic teaching. The pope cannot change doctrine.
Mormon leaders claim ongoing revelation so, for example, it is within their power to declare polygamy doctrine at one point, and contrary to doctrine at another. They have the power to reverse previous doctrine. The pope can't do that.