In its natural form the creature is a gelatinous grey mass of biomass. If it encounters another lifeform and makes physical contact it can assume that creature's form through genetic sampling.
Created by a French Scientist who eventually became "unsound", according to Philip the creature was created as part of a hybridization experiment. Its original purpose was to facilitate the hybridization process of combining DNA to create new lifeforms. However, the creature soon developed a mind of its own and was sealed in a drum and abandoned in the Amazon. A separate creature, its mate, was also imprisoned within a drum at the bottom of a river miles away.
It was accidentally released by a treasure hunter years later and began roaming the jungle in search of its counterpart so it could replicate itself. H.E.A.T. was soon alerted of the situation and went to the lab to deal with the creature. During their search, the creature confronted Monique in the form of an anaconda and impersonated her after fleeing. It soon was able to cause dissension among the members of H.E.A.T. because they no longer knew who was real and who wasn't. However, the creature had a higher body temperature than the original, therefore they were able to expose its cover. It mimicked Elsie and escaped in the form of a monkey (having turned into Nick earlier and pushing the real Elsie into a ditch to preoccupy her), where it headed to the team's boat to reprogram N.I.G.E.L. in order to track down its mate.
The team arrived too late and the Mimic merged with its mate; now the two could use their combined mass to turn into forms of Godzilla-sized proportions. Realizing that their offspring had the potential to replace mankind as the dominant species and the original's violent nature, H.E.A.T. chose to kill the shapeshifter with an anti-cellular harpoon dart. The merged Mimics soon battled an arriving Zilla Junior, and while Zilla eventually gained the upper hand, the Mimics turned into a perfect copy of him. By putting his trust into his bond with Zilla Junior, Nick was able to discover which was the Mimic, and was able to hit the fake. Instead of dying, the giant Mimic lost control of its morphing ability and assumed the form of a giant, deformed, two-headed copy of Elsie. It nearly stomped the team underfoot, but Zilla Junior tackled the man-made monster to land and used his atomic breath to roast it into ashes.
- The DNA mimic is capable of transforming into any living organism it has encountered, provided it touches it first. It is also capable of mimicking the clothing, accessories etc. of something it mimics.
- The Mimic is able to absorb and store the DNA of anything it comes across.
- The Mimic is able to access memory and ability of anything it mimics. For example, it uses Dr Mendel Craven's robotics knowledge to program N.I.G.E.L. to find its hidden mate. It also manipulates Randy's attraction to Monique for the former to reveal the location of its mate.
- Since the creature has a higher body temperature than the normal 98.6 in humans it is easy to discern who a Mimic is through proper testing.
- There is a special virus that the H.E.A.T. team specially designed to rip the creature apart at a genetic level. While it didn't kill the monster, it weakened it enough for Zilla Junior to burn it to ashes.
- A Rottweiler named Tiego
- An anaconda
- A condor
- Nick (unseen)
- A panther
- A monkey
- An alligator
- A giant piranha
- A giant bee
- A giant anaconda
- Zilla Junior
- Two-headed Elsie Chapman clone
- The Mimic pays tribute to the short story Who Goes There?, which was about an alien lifeform that was able to imitate the DNA of any living being it encountered. It was the basis for John Carpenter's The Thing. The scrapped monster Barubaroi also appears to have been inspired by the same story.
- At the beginning of the episode, there is a "chimera" in a glass jar, in the same building where the DNA Mimic was found. This could suggest that the episode was partially inspired by the plot of the original American Godzilla remake, scheduled for 1994. There is a creature in the script called "The Gryphon" that starts out as a silver blob that can assimilate other creatures and "mold" them into a new one.
- Its giant bee form shares the same appearance of the Giant Mutant Bee drones.