In Burmese this would be to-aung (bull/lion) or in Thai it would be singha style. A singha is a mythological, lion-like creature from Thai Buddhist mythology. These weights were produced in a range of different designs, primarily based on animals or creatures from local religion/mythology.
These handmade opium weights were used not only as units of opium measurement, but used in everyday transactions where items were traded by weight. They were produced in a series from very small weights to much larger sizes. Although the units of measurement do not correspond neatly to western scales of measurement, there is a proportional relationship, between the various sizes in a series.