Baldy Long Legs

The Baldy Long Legs (Pseudoarachnia calvitium) is a tropical counterpart to the Shaggy Long Legs, as both supposed species are found within the same tropical areas on occasion.

Biology
It's speculative whether or not this creature is its own species, scientists pointing out that Baldy Long Legs are more often found when Shaggy Long Legs are shedding. They've also pointed out that a hairless Shaggy Long Legs looks almost identical to the Baldy Long Legs. This is further supported by Captain Olimar himself, noting how it's classified as its own species simply due to the hair not growing back on a Shaggy Long Legs specimen.

The only thing that supports this being its own species is that the ligaments are light green whereas Shaggy Long Legs are pure black to match the rest of the body.