BFDIA 5b marks the second time in the Battle for Dream Island series where a copyrighted character is used in a way beyond simply being a recommended character (fan characters that are submitted to the production team by fans of the series to potentially appear in official content). Specifically, the 31st level in the game "Encounter" features Lego Brick, who first appeared as a recommended character in the Battle for Dream Island episode "Vomitaco" and is a reference to the LEGO toy brand. The first instance was in the episode "Reveal Novum", where Dora (a stick figure based on the titular character from the animated series "Dora the Explorer" who also first appeared in the episode "Vomitaco") was one of the recommended characters who had a chance to join the competition, but failed due to only having nine votes: she would, however, compete in the show's second season "Battle for Dream Island Again". Additionally, a copyrighted character appearing in a major role would not happen again until years after BFDIA 5b's release, with the release of the spinoff series "BFDI Mini Replicas". In that series, one of the contestants is Ender Rocky, a variant of the main series contestant Rocky who first appeared as a recommended character in the season one finale "Return of the Hang Glider" and is based on the Endermen from Minecraft.