<unk>  tongue largely occurs in the central part of the dorsal tongue, just anterior (in front) of the circumvallate papillae, although sometimes the entire dorsal surface may be involved. Discoloration usually accompanies<unk>  tongue, and may be yellow, brown or<unk> . Apart from the appearance, the condition is typically asymptomatic, but sometimes people may experience a gagging sensation or a bad taste. There may also be associated oral malodor (intra-oral halitosis). The term "melanoglossia' is also used to refer to there being<unk>  discolorations on the tongue without "hairs", which are also harmless and unrelated to<unk> .
Black hairy tongue
Crenated tongue
Fissured tongue
Caviar tongue
Omphalolith
Perryville Tree engravings
Macrodontia 
Chattering teeth