After 25 seasons of having a “wonderful kind of day”, fans are saying a final “goodbye” to “Arthur“.

The beloved cartoon series concluded with a final four episodes premiering on Monday, Feb. 21.

“Arthur” began life in Marc Brown’s Arthur Adventure book series in 1976. In 1994 the author was approached by PBS affiliate WGHB Boston to adapt the books into a TV series, which debuted in 1996.

The show was produced in Canada, with voice actors working in Toronto and Montreal.

Over the years, many celebrities have made guest appearances on “Arthur”, including Yo-Yo Ma, Art Garfunkel, Matt Damon, Alex Trebek, Philip Seymour Hoffman, and more.

READ MORE: ‘Arthur’ Cancelled: Iconic Children’s Show To End Record-Breaking Run With Upcoming 25th Season

Monday’s series finale, “All Grown Up,” flashes forward 25 years to reveal the characters as grown-ups. 

Many fans took to Twitter on Monday to share their reactions after watching:

All 25 seasons and more than 250 episodes of “Arthur” continue to be available on PBS KIDS. 

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