Wolf O'Donnel is a StarFox character who appeared in Brawl but was cut for SSB4. This is most likely because he was portrayed as a clone of Fox.
Wolf is most famous for being extremely short tempered and hot-headed. He is easily baited by trolling and as a result has a very pessimistic view on life. Many people are sympathetic towards him because they see him as a victim of bullying, but others like Fox and Falco brush it off by saying he deserves it.