In Brazil we have the expression "cagão" which can translated as "big shitter" to refer to someone who encourages or announces a firm, dangerous or exemplar behavior but recedes back when need to assume it arrives.
The joke goes: A young man visits the family of his girlfriend for the first time. At one point the father of the girl pulls him aside and tells him that he is no good for his daughter. The father wants a rich man for his daughter. He tells the young man "you can't buy my daughter a nice house, you can't buy her a nice car, you can't buy her nice clothes, I bet you can't even afford to buy her toilet paper". Later, as the young man and girl drive home she notices he is upset. She asks if her dad maybe said something to him. He said, yes, he told me you are a big shitter.
Interestingly, in American English, we would refer to someone who lies a lot as a "bullshitter" or "full of shit", but someone who is cowardly is a "chickenshit". It sounds like "cagão" is a bit of a combination. Either way it seems like one of those universal human cultural tendencies.
*kakka- also kaka-, Proto-Indo-European root meaning "to defecate." According to Watkins, "imitative of glottal closure during defecation."
Another example is "to eat" or "tasty": English yum, Russian nyam etc.
My iraqi friends say baba and arabic is certainly not originated from latin.