Final answer:
Elmo won the Grammy for the best music album for children in the years 1999, 2000, and 2002.
Step-by-step explanation:
The Muppet who won the Grammy for the best music album for children in 1999, 2000, and 2002 is Elmo. This character is a beloved fixture on the children's television series Sesame Street and is known for his friendly and innocent personality. Elmo has been a significant part of children's educational entertainment, contributing to the program's objective to educate and foster the development of young viewers.