Cryptorchidism is a relatively common and important clinical entity and can lead to an array of downstream complications if it is not corrected in a timely manner, most notably with the development of testicular germ cell tumors. However, beyond the development of malignancy, there are other rare complications associated with cryptorchid testicular germ cell tumors which are more commonly seen in females with ovarian germ cell tumors, including torsion, rupture, and paraneoplastic syndromes. Presented is an instructive case (with literature review) of a patient who presented with NMDA encephalitis due to a torsed mixed germ cell tumor of an undescended testis, which subsequently ruptured leading to growing teratoma syndrome.