The first costume is a Latter-Day Saint who is not permitted by the church to use birth control (or to dance).
The second costume requires two guys in costume. One goes as Albert Einstein and the second goes as James E. Talmadge.
Well, the obvious would be a guy with 15 girls. But no, too obvious.
Who is that guy at the end of the BOM? Shiz? Go as a headless man, gasping for breath.
Or Ammon. Walk around with an armful of arms.
Or Nephi. Would a hand buzzer be enough for that one?
Captain Moroni - rip off your t-shirt and wave it on a pole.
Or get an old time beard and go as an early prophet.
Who was the wife that Emma threatened to push down the stairs? Go all bandaged up.
Oh, oh! Top hat and a big cigar - Brigham after a talk on the Word of Wisdom (or was that Joseph what did that?)