Yoshi

Appearances
His first appearance was in Merry Christmas! And was a minor character in School Part 1! Overall: 11 episodes.

Age
Yoshi is 8, which makes him a year older than Speedy. That would be the case, if Yoshi's age wasn't changed to 12 in the Season 2 finale.

Birth Date
In the cancelled episode Happy Thanksgiving! Sonic asks if there are any dinosaurs that were born on April 30th, and Doofy-Shrek replies saying: "my roommate.", referring to Yoshi.

Death
Yoshi died in the Season 2 finale, he faded away, and his last words were "I don't feel so good either..."