“Mardi Gras Indians are African-American Carnival revelers in New Orleans, Louisiana, who dress up for Mardi Gras in suits influenced by Native American ceremonial apparel.” from Treme Indians
This article also uses the phrase “masking as Indians” which sounds very similar to some avatar performances. I’ll look into Carnival a bit more in future, it was something I explored a while ago, but these things do have a habit of coming round again in cycles.