Lupine Harbingers is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Trample, haste Lupine Harbingers enters the battlefield with X +1/+1 counters on it, where X is the number of turns you've begun since it was foretold. Foretell (During your turn, you may pay and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)