DS3 is almost 2yo and loves DS1's backpack. We'd like to get him one for his birthday or Christmas. It will be mostly used for play. Doesn't need to carry a lot. We won't use it for daycare/ preschool. It doesn't need to be useful for elementary school. It doesn't need to have a leash. What do you have? Avoid it or recommend it? The search function didn't offer much.
I think the ones from Bratsacks baby are cool looking. We don't have one, but I do have a messenger bag by the same vendor and it has held up well. link
I got this Dabbawalla backpack for DS for Christmas. It is so cute! And the whole thing can go right in the washing machine, it's made out of wetsuit like material and seems to be very durable. The dog was on sale for $16, I probably wouldn't have spent $30 on it because I'm cheap but it is really good quality and worth that much.