One that is weighty
Even baby zebras have been discovered to be huge. Despite its little appearance, the newborn weighed around 40 kg (70 pounds). It would have outgrown the guys and made the rescue nearly difficult if it had been an adult zebra.
In this case, though, the two guys were significantly bigger than the zebra, and they had no trouble rescuing him. The infant would not have survived if the men had been weak and did not have a strategy like these two heroes.