My Bionicle world is filled with many species, a number of which are sentient. To try and make things clearer for the future, in this post I will highlight some of the more prominent sentient species in this world.
Okotans
Originating from the region of Okoto, this species of bio-mechanical man averages at only three feet tall in their natural state. Where they lack in height they compensate with limited elemental control, typically correlating to the region they were born (see chart below). Once an Okotan is fully mature, they have the potential to turn into toa (not to be confused with Toa, the political party), enhanced beings who have doubled in size and have gained significant control over their particular element.
Almost all Okotans are seen wearing a Kanohi mask of their choosing. These masks serve a number of purposes on Okotans; the main ones being (1) they provide a power specific to the mask and (2) enhance the wearer’s elemental abilities when worn and hinder them when not.
Notable Okotans include: Miserix, Mutran, and Cojera.

Mutran (left) is an ordinary Okotan while Mengele has transformed into a toa.
Notable Okotans who have turned into toa include: Madilim, Pragna Vyza, Teridax, Settel, Nantu, and Mengele.
When a toa reaches the senior years of his or her life, they can change once again into
turaga, shrinking down to two-thirds of their previous size and sacrificing a majority of their elemental abilities. Where they lose physicality, turaga gain wisdom. I have no notable turaga characters at the moment, which is why I saved this section for last.
Marlinans
Marlinans come from the northeastern most part of the world, naming the place they originated from after themselves. The species towers over their cousins, the Okotans, averaging between five-and-a-half to eight feet tall. Unlike Okotans, however, Marlinans lack elemental powers, instead they rely on their natural strength and agility to get the job done. Also distinguishing Marlinans from Okotans is that they do not undergo a metamorphosis-like process that the Okotans do (base Okotan -> toa -> turaga); with Marlinans, what you see is what you get.

Dannato Yuuzhan
Similarly to Okotans, Marlinans are typically seen wearing Kanohi. That said, the Kanohi are not ingrained in Marlinan society as they are in Okotan culture, only entering relevance less than a millennium ago; even then many Marlinans choose their masks based on their design rather than their functionality.
Notable Marlinans include: Natale Mortalis, Benedict Attarai, Antaedymn, and Dannato
Yuuzhan.
Rahkshi
Rahkshi are a rare species of insectoids scattered across the planet. These bugs are an anomaly among sentient species because they follow a pack mentality like those commonly seen in wolves. Rahkshi will form groups between six and twelve members, from which one (typically the oldest) is deemed the Alpha and leads the group. Another

Vorahk in the foreground is being observed by Guurahk, another Rahkshi, and Madilim, a toa, in the background.
member, deemed the Beta, takes second-in-command. Similar to Okotans, Rahkshi have powers connected to their biology, but they are not elemental, rather controlling things such as fear, anger, poison, shattering, etc.

Panrahk
Because the species is rare, this is almost all researchers can definitively say about them. No one is certain if their powers are the same across the different types of Rahkshi (such as how all toa originating from Ta-Lachia will be toa of fire) or if said powers are unique to the individuals. There simply isn’t enough evidence to conclude one way or another.
What is known about Rahkshi is that, unlike most insectoids, they are vertebrates. As a matter of fact, their pronounced spines are a species defining trait. Up until a few years ago, a species called the Owadinen (pronounced oh-WAH-dih-nen) (which looked very similar to Rahkshi, albeit lacking their signature spine) was considered one half of the Rahkshi species, believing sexual dimorphism was the reason some had spines and some did not. This theory was disproven when both male and female Owadinen were discovered.
Notable Rahkshi include: Turahk, Kurahk, Vorahk, Guurahk, Lerahk and Panrahk.
Notable Owadinen include: Zalon.
Unidentified Species

“The Bird” (left) is of an unknown species, while Kalther is a Marlinan.
There are also a number of characters who come from

“Seven Alarm”
species which I haven’t bothered given a proper name to as of yet. Many of these individuals are the only noteworthy member of their species, leaving it up for debate whether naming the species is even necessary.
Trivia
- Marlinans and Oktotans are similar enough genetically that the two species could breed and the resulting child would develop fairly normally without much issue.