The story My Brother Was A Robot from My Greatest Adventure #42 (April 1960) is uncredited but I suspect it may be from the mind or editorial office of Otto a.k.a. Eando Binder, a former participant in science fiction pulps of an earlier era who did some work for DC. While working at DC, Otto had a habit of recycling some of his ideas, particularly those of his popular pulp creation the robot Adam Link, into his later comic book works.
I’m presenting My Brother Was A Robot here not because it is particularly good, the plot is pretty dull actually and is an otherwise forgettable entry into the annals of comic history. What makes this story worth noting at all is that it features a robot beating the crap out of some crocodiles and a gorilla. Sometimes comics just don’t get any better than that.