PBS Kids has had several groups of 'mascots over the years.
P-Pals
The P-Pals are similar to the PBS logo, they were introduced on PBS Kids first air date when it was called PTV on October 11, 1993 and were dropped on September 5, 1999 after nearly 6 years on PTV and were replaced with Dot and Dash when it was relaunched as PBS Kids.
Dash and Dot
Dot & Dash, along with their friends (who were NEVER used as actual mascots)
Dash and Dot are two green kids with black hair and both wear on similar clothes with white shoes. They were introduced on September 6, 1999, replacing the P-Pals and were dropped on October 6, 2012 after 14 years on PBS Kids and were replaced with a redesigned and older version of Dot along with 2 new mascots, Dee and Del However, some idents, promos, and bumpers still aired until March 2014, most still air today. Prior to there names, they were originally named PBS Kids Boy and PBS Kids Girl before the Miss Lori and Hooper block on Labor Day 2006.
Hooper
Hooper is the third mascot of PBS Kids, he was introduced on September 6, 2006. He is a brown guinea pig with circular glasses (similar to the ones that Arthur Read wears). Like Dash and Dot, he is a popular mascot, however, during the re-brand, some of his interstitials was still intact.
Dot, Dee, and Del
Twins Dee and Del were introduced on October 7, 2013, during the re-brand. They are Dash and Dot's new younger siblings. Their big sister, Dot, now several years older than 2000s Dot, is always taking care of and babysitting them and their big brother, Dash is absent from the bumpers likely since he was getting too old to be an official mascot. However, Dash, still appears in the familiar PBS Kids logo and he did make a surprising return in a Word of the Week promo.
The song Brothers and Sisters which they appear in reinforces that they are siblings.