Leptolalax arayai inhabits the primary forests of Gunung Kinabalu, Trus Madi, and Crocker Range, from approx. 400–1.700 m asl.
It is a medium sized frog (30–40 mm) that lives along the banks of mountain streams. The upper side is brown, grey or olive with dark markings. The groin region and the upper sector of the iris are red-orange.
Males usually call 2–10 m away from the stream, sometimes on the ground, but more often from low vegetation. The lound call can easily be confused with that of a cricket.
Reproduction takes place in small to mid-sized streams. As in other species within the genus, tadpoles are highly specialized interstitial burrowers. They live among the gravel in superficial layers of the streams and are very difficult to find. ...it took us years!
The tadpole is long and slender. The tail is strong and the tail fins are low. The oral disk forms a cup-like structure. The eyes are small.