
Other Merfolk creatures you control get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)
Master of the Pearl Trident has 5 printings, first in Magic 2013 (2012). EDHREC ranks it #3,524 among Commander cards. It appears most in Hakbal of the Surging Soul decks (24,021 on EDHREC). 1 public deck on TCG runs it. It has 1 official ruling.
Deck counts from EDHREC.
Cards that show up in the same decks on EDHREC.