Zombie Researcher

Zombie Researchers are the researchers onboard the B.S.L Research Station that have been infected by the Template:X. They appear only on the Main Deck. Like several other creatures encountered that have combined DNA, they are likely a combination of human DNA and that of a slime creature. Zombie Researchers are weak compared to many other X mimicked creatures that Samus encounters, being defeated by a single shot from the Power Beam. After being destroyed, Zombie Researchers release either a Template:X or a Template:X.

Although X-mimicked humans seem to transform into Zombie Researchers, one dead human mimicked by the Wide Beam-wielding Hard Core-X did not transform into a Zombie at all. Instead, it looked like a normal human before it transformed to its true X form.

Manual

Manual info from Metroid Fusion

Zombie Researcher:

These shambling creatures are probably the result of X parasite absorbing a slime creature's DNA then infesting the staff researchers. They're remarkably similar to zombies.