Diguises in the Book of Mormon

Nephi

Nephi murdered Laban and then put on Laban's clothes as a disguise. It fooled Laban's servant and even Nephi's brothers.

Therefore I [Nephi] did obey the voice of the Spirit, and took Laban by the hair of the head, and I smote off his head with his own sword. And after I had smitten off his head with his own sword, I took the garments of Laban and put them upon mine own body; yea, even every whit; and I did gird on his armor about my loins. And after I had done this, I went forth unto the treasury of Laban. And as I went forth towards the treasury of Laban, behold, I saw the servant of Laban who had the keys of the treasury. And I commanded him in the voice of Laban, that he should go with me into the treasury. And he supposed me to be his master, Laban. 1 Nephi 4:18-21

And it came to pass that when Laman saw me he was exceedingly frightened, and also Lemuel and Sam. And they fled from before my presence; for they supposed it was Laban. 1 Nephi 4:28

Abinadi

Abinadi had such a great disguise that no one recognized him for two years.

And it came to pass that after the space of two years that Abinadi came among them in disguise, that they knew him not, and began to prophesy among them. Mosiah 12:1

Kishkumen

After Kishkumen murdered Pahoran he had a disguse so that no one could recognize him.

Kishkumen was not known among the people of Nephi, for he was in disguise. Helaman 1:12

One of the servants of Helaman

One of Helaman Jr.'s servants learned about a plot to kill his master by wearing a disguise. (Works every time.)

Behold one of the servants of Helaman, having been out by night, and having obtained, through disguise, a knowledge of those plans which had been laid by this band to destroy Helaman. Helaman 2:6

The chief judge was murdered in the "garb of secrecy" by his own brother.

Now, immediately when the judge had been murdered -- he being stabbed by his brother by a garb of secrecy. Helaman 9:6