In the U.S. there is no "dominant" sign for "panda" as in a "panda bear."
If telling a story, you would spell the word "panda" and, if necessary, describe
it using signs like: CHINA, BEAR, BLACK, WHITE. Then as you tell the story
you would simply use the sign BEAR to mean "panda bear" because you have already
identified the bear as a "panda bear" at the beginning of the story.
You might use a phrase such as,
"You know, there in China, they have a bear that is black and white.
"you know" = know
CHINA (new version)
Make a clawing movement at your chest. Repeat.
Note: Do not practice this sign on other people.
Note: Some people might try to tell
you that in ASL you should sign "BEAR" first and BLACK / WHITE second.
While that grammar structure is one of the correct ways to sign this concept, it
is also correct to sign "black" and "white" just before signing "bear."
The ASL Linguistics book by Vali and Lucas is quite clear on the concept that
certain adjectives can precede nouns in ASL. (For example, "YELLOW