And often its use comes with the implicit judgment of Western superiority wherein "shaman" is applied to the spiritual leaders of "primitive" cultures. (I suspect that most fantasy depictions of "shamans" will probably have them as "primitives" wearing bones, feathers, fur, and other trappings, no?)
This is true of its usage in D&D.
In 5e, stone giants, lizardfolk, and quaggoths have shamans. The stone giant in the MM wears animal skins and wields a club. They also fight with thrown rocks. Lizardfolk are "primitive reptilian humanoids" with INT 7. They use simple weapons such as clubs. "Though they aren't skilled artisans, lizardfolk craft tools and ornamental jewelry out of the bones of their kills, and they use the hides and shells of dead monsters to create shields." "[T]hey have a taste for humanoid flesh", devouring their victims in "great feasts" if they’re not "sacrificed to Semuanya, the lizardfolk god." Quaggoths, INT 6, are "brutal and savage", were "never an enlightened species", and practise cannibalism. They do not use weapons but attack with their claws.
In 1e AD&D shamans are one type of "tribal caster", the other being the witch doctor. Shamans are like clerics but have a much more limited spell selection. They are never human but are found among bugbears, ettins, giants (hill, fire, frost, stone), gnolls, goblins, hobgoblins, kobolds, lizard men, ogres, orcs, troglodytes, and trolls. Only two of these, stone giants and hobgoblins, have average intelligence (8-10). The rest are lower, and many - ettins, hill giants, 90% of lizard men, ogres, trolls, and troglodytes - are of low intelligence (5-7). For comparison, gorillas and whales also have low intelligence.
Ettins wear "animal skin dress". Hill giants "typically dress in rough hides or skins". Gnoll "armor is of horn, metal plates, and leather". Goblins "dress in dark leather gear". "All kobold shields are of wood or wickerwork." The lizard man is depicted wearing only a skull and tooth necklace. "Ogres wear any sort of skins or furs." Trolls wear no clothing. The troglodyte is depicted in only a harness.