Tama
A small black cat, a pet of Dr. Briefs that is always seen sitting on his shoulder. "Tama", which is "Ball" in Japanese, is suggested to be a female, although nothing official has been stated on the cat's gender (In the English dub, however, Tama is female, referring to a quote by Dr. Briefs; "This is no ordinary cat! She's had 5 years experience!"). It is also suggested that Tama knows about how machines work and can be fixed, but the lack of speech would pose quite an issue.