Following are a number of back-translations as well as a sample translation for translators of Isaiah 14:29:

• Kupsabiny: “Do not rejoice, oh, Philistines,
  Do not rejoice that the stick that you were beaten with has broken.
  When a snake has died, another who is worse than it shall replace it.
  An animal that flies can come from the egg of a snake.” (Source: Kupsabiny Back Translation)
• Newari: “O all [you] Philistines,
  do not rejoice that the stick that struck you is broken,
  for if one snake dies,
  another poisonous snake will come in its place.
  From its matter a more poisonous snake will come out.” (Source: Newari Back Translation)
• Hiligaynon: “Filistinhon, you (plur.) do- not -rejoice because the king who had-attacked you (plur.) died. For his child will-succeed him is more harmful than him, like a snake who was born from him a more venomous snake that seems-like flying.” (Source: Hiligaynon Back Translation)
• English: “You people of Philistia, do not rejoice that the enemy army that attacked you has been defeated
  and that their king is dead.
  He was as dangerous as a snake,
  but there will be another king,
  who will be more dangerous than a cobra;
  he will be like a quick-moving poisonous snake.” (Source: Translation for Translators)