"There is a small rocky islet or group of rocks near the SE. Point of P. Ubin called S'kodo, from a fancied resemblance of one of the blocks to a frog. Those in the middle are large and connected by sand in which some shrubs grow, and those scattered around are smaller and much worn by the waves. Some large rocks also lie in the sea on the south side of the central collection, and the longer sides of those run S.W. by W., N.E. by E. Parallel reddish lines or bands about half an inch broad traverse the surfaces and mark the planes of weaker cohesion. The sides of some of the blocks are peeling off in parallel layers. In some, another set of divisional planes, transverse to the former, are well marked. Where the rock is breaking down, these two systems of planes divide it into rhomboidal fragments."
– James Richardson Logan (1846), 'The rocks of Pulo Ubin, with some remarks on the formation and structure of hypogene rocks and on the metamorphic theory.' Verhandelingen van het Genootschap van Kunsten en Wetenschappen, vol. xxii. Batavia.
"The above is a rock which, at low tide, bears a remarkable likeness to a frog squatting. It is situated, with some other and larger rocks, in the old Straits of Singapore, between Changi and the eastern end of Pulau Ubin, near the latter. The local account of its origin is that, when mosquitos were as big as fowls, frogs were large in proportion, and that the living original of the rock in question in those days ventured a swim across the Straits, but before he could reach land daylight appeared, and the adventurer was turned to stone where he was."
– D. F. A. Hervey (1883), Batu Kodok (The Frog Rock), in Miscellaneous Notes, Journal of the Straits Branch of the Royal Asiatic Society 11.