The name of the common error in the following sentenece?

My answer is Dangling Modifier... Is that correct?
Thank You

1.The dog that is man's best friend, is cat's worst enemy.

There's no dangling modifier here.
http://grammar.ccc.commnet.edu/grammar/modifiers.htm

There should be either no commas or two commas between a subject and its verb. In this case, there should be no commas at all if "that is man's best friend" is being used as a restrictive clause -- or else there should be two commas if it's being used as a non-restrictive clause.
http://www.uottawa.ca/academic/arts/writcent/hypergrammar/comma.html
See the first example given after Superfluous Commas. See also the explanation for number 4 in Comma Usage.