Variant muscle slips arising from the pectoralis major or the latissimus dorsi muscle have been described before. Here in these report, we present a rare case of aberrant muscular slip originating from the pectoralis major called as the “thoracoepicondylaris” and an unusual slip from the latissimus dorsi called as “axillary arch of Langer” to have a common insertion after arching superficial to the axillary neurovascular bundle into the fascia covering the biceps brachii. Clinical consideration of such a variation is discussed since the knowledge of the muscle is important for differential diagnosis.