My understanding is that Glukkons, Oktigi and Gloktigi are all from the
Octigi family of species, with Gloktigi being of animalistic intelligence and Glukkons/Oktigi being sentient.
Sekto keeping Gloktigi as pets could be compared to a human keeping monkeys as pets, and some of the Gloktigi seen in SW were cybernetically enhanced by Sekto. Interestingly though, some of the concept art seems to show them wearing
some kind of suit-like clothing, although this might just be decoration (in the same way a jerk might dress their pet monkey in a costume).
The only reference I can find of Gloktigi being Glukkon/Oktigi hybrids is an uncited footnote on the Oddworld wiki, so take that with a grain of salt until someone else can back it up with a reference.