The two attacks were "Chef's Knife" and "Everyone's Grudge."

Both did an enormous amount of damage... The Tonberries usually had a lot of HP and Evasion stats as well if I remember correctly. The big weakness was that a Tonberry had to move in and use up most of its life before it could get a clear shot with the Chef's Knife. "Everyone's Grudge" was a random retaliation attack that was extremely powerful.