Poptube Shark

I think there might be some confusion! There is no such thing as a "Poptube Shark" food item that is commonly found in restaurants in the USA. However, there are a few possibilities that might be related to what you're looking for:

1. Pop-Tart: Pop-Tarts are a popular snack brand in the USA, and they are often found in restaurants and convenience stores. They're a type of toaster pastry that comes in various flavors.

2. Poke bowl: Some restaurants in the USA offer a dish called poke, which is a Hawaiian-style raw fish salad. Some places might use a creative name like "Shark Attack Poke" or a similar name to entice customers.

3. Fruit cup with sharks: Some restaurants or food establishments might offer a "Shark Tooth Fruit Cup" or a similar name as a way to engage kids or play with food presentation. It might contain a mix of fruit, such as grapes, strawberries, and pineapple, arranged to resemble a shark's teeth.

If none of these sound like what you're thinking of, please provide more details or context about the "Poptube Shark" you're looking for!