Any type of red meat and fish contain Creatine. However, some of the Creatine is lost in the stomach during digestion and when it is cooked. An amino acid called methionine is also important in the making of Creatine. Methionine must be in our diets because it sets an upper limit on Creatine synthesis since the body cannot produce it on its own.
Fish is one if the highest sources of methionine.
Therefore eating fish can be a direst source of Creatine, but again, very impractical.