Mom Tiger aka Collette Tiger is the mother of Daniel Tiger and Margaret Tiger, the wife of Dad Tiger (originally Daniel Striped Tiger in Mister Rogers' Neighborhood) and the daughter-in-law of Grandpere Tiger and Johanna Tiger. She’s never given a first name, leading to speculation her true identity may be Collette Tiger.
Collette Tiger is a light orange tiger, with a medium build and raw sienna stripes. She wears a white V-neck t-shirt with periwinkle flowers, blue calf-length pants and orchid slippers. When expecting her first child, Daniel, she wore a yellow maternity shirt and sunflower barrette, along with her usual pants and slippers. Being pregnant, her midsection expanded considerably, stretching her shirt. In The Tiger Family Grows, it was revealed that she was having another baby. Her stomach gradually swells up throughout the episode, bloating to the point where Daniel can no longer sit on her lap. She wore a light pink robe with a darker pink trim and ribbon. Her large belly stretched the robe, with the ribbon resting atop it.
In Mister Rogers' Neighborhood there was a character named Collette Tiger who was prophesied by a witch to marry Daniel Striped Tiger. It’s possible that Mom Tiger is her, although she hasn’t been referred to as Collette in the show, so it’s unknown for certain.