Hi! Did you want to commission him or make a request? I don't visit his Tumblr page. I usually just visit his FA (Fur Affinity) page, so I don't know what's going on there.
If you read "Getting on an artist's 'good side'" in his FAQ page on FA ->
https://www.furaffinity.net/journal/7561649/, he doesn't do requests easily or at the very first time that someone asks. You have to show true interest in his artwork (By leaving genuine comments) over a period of time before he will even consider doing a free request.
If you want to commission him, his Profile page says that he's currently closed for commissions ->
https://www.furaffinity.net/user/tato. However, it wouldn't hurt to fill out one of his "commission forms" ->
https://sites.google.com/site/tatocomms/ in order to let him know that you would like to commission him in the future. For more about "commission forms" and other rules that the artist wants commissioners to abide by, see ->
https://sites.google.com/site/tatoco...rms-of-service.
I'm just curious - What idea for an artwork did you have in mind to ask of him?