The Adventures of Sir Lancelot the Great by Gerald Morris, illustrated by Aaron Renier

From chapters.ca:
Many years ago, so the storytellers say, the great King Arthur brought justice to England with the help of his gallant Knights of the Round Table. Of these worthy knights, there was never one so fearless, so chivalrous, so honorable, so... shiny as the dashing Sir Lancelot, who was quite good at defending the helpless and protecting the weak, just as long as he'd had his afternoon nap. Behold the very exciting and very funny adventures of Lancelot the Great, as only acclaimed Arthurian author Gerald Morris can tell them.