Not as a normal practice.
Most dogs have tongues that are pink, any of varying shades. However, some dogs, such as the Chow (Chow Chow) have tongues that are black, or at least with areas of dark purple or black.(see the related question and link below)
white people came and hunted them for skin and tongues
That is the tongues version of a scab and it will go away in a few days.
Black cattle like Angus, or cattle with dark pigment (Jerseys, British White, Speckle Park, White Park, etc. ) tend to have black-pigmented tongues. Even Holsteins may have black tongues, but usually only if the rest of their face/muzzle is black. However they can also have tongues colored black and pinkish-beige. Other cattle that are not black or dark-pigmented typically have pinkish-beige to light-pinkish tongues. Tongues appear more pink with white cattle or cattle with white faces than those that are brown or solid red in coat colour.
normal penguins are black and white
If they was white when you got it, then it is normal.
Some dog breeds actually have black (or blue) tongues and gums. Ask your vet if the coloration in your dog is normal or not.
They smell with their tongues
It's the tongues version of a scab it will ease off as the piercing heals, relax.
can people have 2 tongues
Yes,hippos have tongues.