Which sacraments can hermaphrodites validly receive in the Catholic Church?
Hermaphrodites can be baptized.
Regarding 1917 Canon 748 (which has no equivalent in the 1983 Code), which deals with baptism in the case of deformed or abnormal fetal humans, canonist Charles Augustine, O.S.B., D.D., writes in A Commentary on the New Code of Canon Law, on Can. 746:
There is no difficulty as to hermaphrodites, because sex does not affect the validity of Baptism.
Complete hermaphrodites cannot be validly ordained.
Concerning hermaphrodites, it must be said that complete hermaphrodites, whose sex cannot be determined, may not be validly ordained; whereas those with whom the male sex prevails may be ordained validly but not licitly.
Complete hermaphrodites cannot validly marry.
As to hermaphrodites, or such persons as have the sexual characteristics of both sexes, whether it be androgynia or gynandria or hermaphroditismus neuter, the testimony of physicians is required [to determine whether they are sexually impotent or not]. No hermaphroditus neuter can possibly be called capable of marrying because the sex is not sufficiently determined.
androgynia = hermaphroditic with male aspect predominant
gynandria = hermaphroditic with female aspect predominant
hermaphroditus neuter = a complete hermaphrodite (equal male and female aspects)
There are no other canons explicitly forbidding hermaphrodites qua hermaphrodites from receiving the other sacraments (Confirmation, Eucharist, Penance, Extreme Unction).