In Gbaya, the notion becoming rigid as a sign of fear is emphasized in Mark 9:18 with kiŋgiŋgi, an ideophone that describes a sign of great emotion, a panic of fear and helplessness.

Ideophones are a class of sound symbolic words expressing human sensation that are used as literary devices in many African languages. (Source: Philip Noss)

In Q’anjob’al it is translated with the existing idiom “become bony.” (Source: Newberry and Kittie Cox in The Bible Translator 1950, p. 91ff. )