Just citing some theory from reddit. The Spanish for turtle is Tortuga (which was a Pirate base during the days). As for the ninja it hints that it will share gear with Ninja (scouting)

Your caution is warranted. I like most of his works, but I do think his story telling might not be his strongest suit. Don’t get me wrong it’s great but I think where he excels most is in combining music and animation like no other.