Do you really mean terpenoid or do you actually mean hydrocarbon? Terpenoid sort of implies it's constructed from isoprene units, hydrocarbon is the more general term for C, H only.
There are definitely amine analogs of THC, the three classes I can immediately think of being either replacement of the benzopyran ring with a benzoquinoline ring a la levonantradol. adding amine groups to the free phenolic OH somehow (O-1057) or adding amines onto the alkyl "tail" like O-2545.
As for fully hydrocarbon analogs of cocaine, tropoxane seems to be the closest I can think of.
To be truthful, THC is only half terpene. The olivetolic acid group (i.e. the olivetol group - aka 1,3 dihydroxy 5 pentyl benzene) is produced by polyketide synthesis.
And cocaine is not terpene at all: it's derived from amino acids (lysine, phenylalanine, methionine) if I remember right.