Fluke and Rudder are major characters in Finding Dory.
Fluke was voiced by Idris Elba in the English, and by Tessho Genda in the Japanese. Rudder was voiced by Dominic West in the English and by Chō in the Japanese.
They are two big seals. They are very friendly to fish, but they are very unfriendly to another seal named Gerald, who is much smaller than them. They were shown to bark "Off! Off! Off!" (that's maybe parody on Seagulls' saying "Mine! Mine! Mine!") on Gerald whenever he's trying to come to their rock and be their friend. Even through Gerald didn't show his feeling, he's obviously very sad about that, because he just wanted to be their friend. Fluke and Rudder shown how evil they are when they saw that Gerald's got green pale, they let him on their rock for a little time, but that's just because they wanted to steal his pale, and when they stole it, they again barked at Gerald and threw him of their rock. When Gerald successfully got to their rock, they shouted: "Gerald? Are you lost your marbles?" At the end of movie, Gerald won the battle because he finally got to their rock, when were sleeping. But they also shown their heroic side, when Nemo and Marlin were talking to them and told that they need help to rescue their friend Dory. They called their friend Becky and told her to help Nemo and Marlin in their rescue.