What is a type of giant extinct animal?

There are many types of giant extinct animals! To give you a more specific answer, I need more information. What kind of animal are you interested in? For example, are you looking for:

* Mammals: Like mammoths, giant sloths, or giant deer?

* Reptiles: Like dinosaurs, giant lizards, or giant turtles?

* Birds: Like the moa or elephant birds?

* Insects: Like giant dragonflies or giant cockroaches?

* Marine animals: Like giant squid or giant sharks?

Once you tell me what type of animal you're interested in, I can give you a more specific answer.