- "An anteater is a funny-looking animal. From the end of its bushy, feather-duster tail to the tip of its absurdly long, pointed head, it was maybe four or four and a half feet long. It stood as tall as a grown man's knees. [...] But even though the giant anteater is comical, it is not helpless. I was resting most of my weight on my hind legs. I balanced on my front knuckles, the better to keep my wickedly curved scythe claws safe and sharp. I felt the anteater instincts bubbling up beneath my own human consciousness. I braced myself for some extreme fight-or-flight reaction. But the anteater was a calm, lethargic sort of creature. Later I found out they have one of the lowest body temperatures of any land mammal. They're known to sleep as much as fifteen hours a day. But this was not a stupid animal. I had excellent hearing and an excellent sense of smell."
After being shrunk by the Helmacrons in The Suspicion, Cassie asked Ax to fly them to The Gardens, where she, Jake, Rachel and Marco acquired the giant anteater, as new DNA would be unaffected the shrinkage. The technique was also copied by Visser Three, who acquired the giant anteater as well.
- "When the Helmacrons shrank us, they also shrank all the DNA inside us. All the morphs were reduced to that same scale, right?"
"Well, it occurred to me that new DNA, newly acquired DNA, might not be shrunk. [...] At least, I hope. We should be able to acquire this animal we're on and morph it. Full size!"
- ―Cassie and Marco
The giant anteater morph was used by Cassie, Jake, Rachel, Marco and Visser Three to become full-sized again after being shrunk by the Helmacrons. Since the anteater was designed to eat ants, the Animorphs used it to subdue the Helmacrons, while Visser Three used it to attack Tobias, although he was unable to kill him due to Ax's interference.
- The Suspicion (acquired and morphed by Jake, Rachel, Cassie, Marco and Esplin 9466, the latter using Alloran-Semitur-Corrass's body)