A surname common in people from ibero-romance descendence, especially in the north-west regions of Spain like León or Asturias. Carbajo refers to an oak tree as a word. This surname has other varieties depending on the region or country, some examples are Carballo, Carvallo (most common in the autonomous community of Galicia) and Carvalho (mostly found in Portugal). The surname Carbajo is most likely adapted from its Galician version Carballo to match it better with the Spanish language and it's pronounciation.
Mr. Carbajo gave a Pennington Special to that homeless girl he saw in the corner.