He is voiced by Jennifer Hale.
Baby Hugo is Alice's brother. He is very observant and loves to participate. It's clear through his emojis he'll be as bright as his sister one day.
Even though he's a baby, Hugo has shown that he knows a lot of things, and most of the time he realizes things that even adults don't realize, like in "Claus Out, Unicorn!", when he recognized Unicorn disguised as Santa Claus, or in "Smarten Up, Unicorn!", when Dad can't find the car keys to pick Alice up from science camp, Hugo finds them and wants to give them to her, but Dad thinks he's playing and doesn't pay attention to him.
Hugo's skin, hair, and eye color is very nearly identical to Alice, but he wears a pale blue t shirt, a pale yellow bib with a tiny periwinkle blue star image in the middle, and no pants at all (but replaced with white diapers), even no socks and shoes, too.