Kamonohashikamo is often accompanied by Harinezumikana, a little blue hedgehog (or maybe an echidna?) who, like Kamonohashikamo, frequently questions itself, though its favorite phrase is "Kana".
Also frequent companions of Kamonohashikamo are Ahirunano, a pair of mischievous twin ducks. They were hatched from an egg that Kamonohashikamo found, and the twin ducks love Kamonohashikamo like their mother. However, they are afraid of Kamonohashidasu.
The opposite of Kamonohashikamo is Kamonohashidasu, a black platypus who is certain of everything. It always responds sharply to Kamonohashikamo, and speaks flatly. Its favorite phrase is "Dasu" or "absolutely". Kamonohashidasu views the world as "black and white" with no in-between.
(source: http://www.kawaiibuzz.com/2010/07/kamonohashikamo-platypus.html)