There are almost more words in the title than there are in the rest of this spare and poignant book. Small pages reflect the small size of a baby hippopotamus, who is shown swimming, eating, and sleeping with his mother, until they are separated by rising water and a great wave. After a night alone in the water, the hippo reaches shore and is moved by humans to a parklike area. Among the animals inside, he meets a giant tortoise. The text consists solely of conversation bubbles reflecting the variations in emotion as the baby animal first thinks “mama” when he sees his hippo mother, then searches frantically for “MAMA?” in the raging water, and then forlornly wonders “mama?” as he’s transported to his new home. As his situation calms, he again thinks “mama” as he swims, eats, and sleeps by the tortoise, who responds with “baby.” A concluding author’s note describes how a baby hippo swimming in Kenya’s Sabaki River was swept out to sea in the 2004 Indian Ocean tsunami. Found on shore the next day by wildlife officials and local fishermen and brought to a park enclosure, he attached himself to a 130-year-old male giant tortoise, who acts as a surrogate mother to the displaced baby hippo. (Ages 3–6)