"Dollan" is maybe cognate with north Indian "dhol". Drums are usually named with onomatopoeic words.

It's quite likely frame drums have been around in the British Isles pretty continuously since the Neolithic. But what makes the bodhran different from every other drum of that type found in any culture of western Asia is its uniquely incompetent and ineffectual technique. The difference between a bodhran and a bendir is just that a bodhran has to be played badly to be considered traditional.

The link with riddles is not just found in the British Isles - I've seen a workshop in Turkey where they made both riddles and bendirs.

I suggest a logo of the Cerne Abbas giant on the drum, and then you can guess what shape the beater should be.

A Real Man can play it with no hands?