CHARLI D’AMELIO AND AVANI GREGG as MERMAID MAN AND BARNACLE BOY from SPONGEBOB SQUAREPANTS

This BFF costume looks complicated, but it’s actually a bunch of basics put together. For Mermaid Man’s belt, cut an M out of craft paper and tape or hot glue it to a belt. For Barnacle Boy’s cap, Google “How to make a sailor hat out of paper” for a quick tutorial.