under minnesota law, a ballot should not be invalidated if the voters intent is determinable. i think it's pretty clear that this voter believed that the lizard people should be on the ballot but that al franken nevertheless would make a better senator. thus, she or he wrote in "lizard people" but filled in the franken oval (instead of the write-in oval) to cast his/her vote for franken that race.
it's also apparent that the voter wanted the lizard people to be president, not senator (that's the vote above the senate race. baldwin/castle was the constitution party's ticket in the presidential race)
you can puzzle out other challenged minnesota ballots here.
(via skippy)