What does frobscottle and what does it taste like?

Frobscottle is a fictional beverage from Roald Dahl's book "The BFG." It is described as a fizzy, green drink that produces bubbles that go down instead of up, leading to a unique and humorous effect. The taste is often portrayed as sweet and refreshing, reminiscent of a fruity soda, appealing to children and giants alike. Its whimsical nature adds to the charm of Dahl's imaginative world.