This enemy is found in the second installment, partners in time. It can be found in both sections of the Peach's castle (past), being the cellar and upper castle.
The elder of the duo (Shroobsworth) has three attacks. The first is a meteor throw. To avoid damage, hit it back with the hammers. It is countered upon successful rally. His second is where he throws the Intern Shroob in the air and hits you with his cane. It can be dodged, but not countered. His final attack is where he throws the Intern Shroob in the air and the Intern Shroob will shoot its gun. This cannot be countered.