The reverse is unusual in that it includes no text or legend, and the coin itself does not carry a portrait of Queen Elizabeth, unlike the other denominations in the series.
For the record, it is the other way around. Malaysia became independent on 31st August 1957. It's the coins dated 1958-1961 that may be unusual, because they still carry the portrait of Q Elizabeth, though this may have been in a sort of arrangement similar that that of e.g. Canada, Australia and New Zealand.
The Malaya and British Borneo dollar was replaced by the Malaysia Ringgit only on 12th June 1967, but the central bank of independent Malaysia was established on 26th January 1959 as
Bank Negara Tanah Melayu (now
Bank Negara Malaysia.) In other words, the 1962 cent was a coin of independent Malaysia, issued by the Malaysian central bank. The legend "Malaysia and British Borneo" must refer to the currency, not the country as that country no longer existed in 1962. In that, it is certainly unusual and maybe "one of a kind".
Peter