Steve Irwin
I don't recall ever watching Steve Irwin, though I might have seen him on the Tonight Show or similar. I wasn't a fan and so didn't make a point of looking for his appearances. I was certainly aware of him as he became a cultural reference in several places. The place I saw him portrayed was Irregular Webcomic where he appeared in one of the several (mostly unrelated) storylines repeatedly. In a bit of sad irony, the comic for the day he died was this one. The cartoonist noted that and also added this strip which might not make immediate sense to those who do not read Irregular Webcomic.
In the various storylines of Irregular Webcomic Death is not just one character but many. There is the Death by Insanely Overpowered Fireballs, the Death by Swallowing a Giant Frog, and even a Death of Wrestled to Death by Steve. They answer to the head Death. The Deaths have had some experience with Steve due to his many close calls and found it was better to "send him back" rather than have to deal with him. It seems that Death by Being Stung in the Chest by a Stingray didn't get the message soon enough, according to this arrangement.
There has been a mixed reaction to the news. I've also seen a few expressing things... rather less than charitably. I've seen a lot of posts expressing sadness at the news and concern for his family and the animals that he did care for. There were the initial posts expressing simple shock. One post stands out. It's the one where drharper tells the story of An interesting day at the Rainbow Bridge.