I've got 2 peacocks with my two oscars, and no problems. One was introduced about 6-7 months ago and the other was introduced about 3 months ago. No problems for me. There was the initial 'curiosity' but nothing I was worried about. My eels were larger then the oscars at introduction though. Both are about 5-6 inches. The first was introduced when the oscars were about 2-3 inches long, and the second when the oscars were about 4-5 inches long.