Hostile encounter. Followers of a god are persecuting unbelievers, you had a direct or indirect interaction with them. (work with your DM to determine details)
Wild carnivorous beasts invade the character's camp. During the attack, the character finds that he has the innate ability to command wild beasts (not monsters) to do his will (so long as it does not seriously risk the animals' lives).
You become involved with criminal elements of society, taking to a life of crime and earning a notorious reputation and bounty. (work with your DM to determine details)