Usagi Yojimbo is an AMAZING indie comic series and I would highly recommend you read it. Like me it came to life in 1984 and while it has hopped around a few companies, it’s still gone strong for nearly 30 years (bar the hiatus it’s taking at the moment, although I felt fans weren’t properly informed as for a while I had started to fear the series had been cancelled without any proper notification).
The original version can be found here (I only saw this here), however I had a bit of a derp moment when I originally post it and didn’t think to Google the artist’s name from the signature… My mistake!
Oh, and the character is called Miyamoto Usagi (last name, first name). Usagi Yojimbo is the name of the comic he stars in. It would be like calling Superman “Action Comics”. The character is also owned by Stan Sakai, and only appears in TMNT crossovers due to a personal friendship he has with one of the creators (I believe it’s Peter Laird but I could be mistaken). I bring these up because people often refer to the character with the wrong name and assume he belongs to the TMNT franchise.