Scanned-in images of two seals with the same inscription but different animals from John Marshall, Mohenjodaro and the Indus Civilization, 1931, Vol. III, Plate CIX #252 and Plate CXII #378. The photos in the original are small and of poor quality, but are clear enough to show that the inscriptions are identical but the animals are not. Vol. II, pp. 382, 389, identifies the animal on the left as a garden-variety "unicorn" and the composite animal on the right as "a ram, with the horns of a bull, a human face, and the trunk and tusks of an elephant."
The tables in Marshall Vol. II, pp. 403-4, show that the two seals were found at exactly the same depth and location at Mohenjo-daro. Both seals have perforated bosses on the backside, suggesting that they were threaded and worn, possibly as personal IDs. The fact that two seals with identical inscriptions but different animal icons show up at exactly the same site casts doubt on the common assumption that the inscriptions on perforated seals like this were probably personal names.