01 - Whisk together milk, cream, sugar, cocoa powder, and salt in a medium saucepan. Heat over medium heat, stirring constantly, until hot and sugar is completely dissolved. Avoid boiling.
02 - Remove saucepan from heat and stir in vanilla extract until fully incorporated.
03 - Pour mixture into Ninja Creami pint container. Allow to cool to room temperature, then cover and freeze for 8 hours or overnight until solid.
04 - Process frozen base in Ninja Creami using the Ice Cream setting until smooth and creamy.
05 - Create a well in center of ice cream. Add marshmallow fluff, caramel sauce, and chocolate fish or pieces into the depression.
06 - Reinsert pint and run Mix-In setting to swirl toppings throughout ice cream.
07 - Serve immediately for soft-serve texture or freeze 1-2 hours for firmer scoops.