We do not currently know of any antonyms for chicken turtle.
The noun chicken turtle is defined as:
Deirochelys reticularia, an uncommonfreshwater turtle found in the southeast of the United States, similar in appearance to the eastern painted turtle (Chrysemys picta picta, but with an unusually long, striped neck, a yellow stripe on each of its legs and a net-likepattern on its carapace.