What makes a white tiger mammal?

The question is a bit misleading. A white tiger is not a separate species of mammal. It's simply a color variant of the Bengal tiger, a species of mammal.

Here's why:

* All tigers are mammals: This means they share certain characteristics with other mammals, like having fur, giving birth to live young, nursing their offspring with milk, and being warm-blooded.

* White tigers are not a new species: They have the same biological makeup as other Bengal tigers. The white color is due to a rare recessive gene that affects their pigmentation.

So, a white tiger is a mammal because it belongs to the species of Bengal tiger, which are classified as mammals.