Dyma gewri byd y slefrod môr a’r creaduriaid anhygoel yma yw slefrod môr mwyaf y DU! Mae’r slefren yma’n gallu tyfu i faint clawr bin sbwriel – gan roi iddi ei henw cyffredin arall: slefren fôr…

The White admiral is a striking black-and-white butterfly with a delicate flight that includes long glides. It prefers shady woodlands where it feeds on Bramble.

The chocolate-brown, plump dipper can often be seen bobbing up and down on a stone in a fast-flowing river. It feeds on underwater insects by walking straight into, and under, the water.

Weasels may look adorable, but they make light work of eating voles, mice and birds! They are related to otters and stoats, which is obvious thanks to their long slender bodies and short legs.

A breeding bird of fast-flowing, upland rivers, the grey wagtail can also be seen in lowland areas, farmyards and even towns in winter.