Mercurial

mercurial |mərˌkyo͝orēəl|
adjective
1 (of a person) subject to sudden or unpredictable changes of mood or mind:
his mercurial temperament.

Henry_emotions_04.07.13
So far Henry seems to have a mostly easygoing disposition, but like any infant, he runs the gamut of emotions as indicated in these pictures taken within about a minute of each other by Jacqui’s coworker, Mallory, when she babysat him the other night.