Amolops himalayanus

The Himalaya sucker frog, also called the Himalaya cascade frog, is a frog found in north-eastern India and Nepal. Whether it is distinct from the Assam sucker frog is still debated (Wikipedia, general species account).

That is all the source opened says. It does not name Bhutan, and no description, size, habitat or breeding information was found, so none is stated. Its presence in Bhutan is flagged for checking, and the entry is kept as short as the evidence allows.