Transgender is also an umbrella term: in addition to including people whose gender identity is the opposite of their assigned sex (trans men and trans women), it may include people who are not exclusively masculine or feminine (people who are genderqueer, e.g. bigender, pangender, genderfluid, or agender).
Chapman holds the record for the fastest recorded pitch speed in MLB history at 105.1 mph (169.1 km/h) as well as the Guinness World Record for fastest baseball pitch for a male.
I think Billy Hamilton of the Reds is generally acclaimed as the fastest man in baseball at the moment. The Marlins' Dee Gordon and the Royals' Jarrod Dyson and Terrance Gore (currently in the minors) are also in the running. Video: Hamilton scores on sac fly. Plenty more videos of Hamilton here.