Now I 've learned that he (or she) was in the "sexually immature land phase" called an Eft - Red Spotted Eastern Newt (Notophthalmus viridescens).
The Eastern Newt (and its close relative the Striped Newt, N. perstriatus) are unique in that they undergo two metamorphoses. The first is the usual transformation from aquatic, gilled larva to an air-breathing terrestrial form. However in these two species there is a second, less striking metamorphosis to a breeding aquatic adult. The sexually immature land phase is usually called an Eft while the aquatic adults are called Newts. ... Adults reach lengths of nearly 5 inches, while Efts usually reach only about 3 inches. The Red-Spotted Newt gets its name from the many red spots that occur on its dorsal surface against the background color of brown to olive green in adults.
The Eft stage may last anywhere from 1-7 years. Sometimes the eft stage is skipped completely and they go directly from the larval to the adult aquatic stage. ... The skin of the Eft is toxic and their bright coloration serves as a warning - it is not so rare to find an Eft wandering about in broad daylight after rain. When Efts transform into adults the red background color changes to olive green or brown, but the red spots remain. They also develop a more compressed tail that helps them swim in the aquatic environment into which they move. (USGS Northern Prairie Wildlife Research Center)