The same way that a stamp has value, or how a trading card has value, someone is willing to buy the asset. Sometimes it is a unique feature, like a specific run, or a misprint, and other times it is utility, but as long as people are interested in purchasing the, in this case "unique" asset (each cat is basically a programmed token with it's own DNA) then it will have a value.
Are people still dealing with them? On a serious note how's a cat cartoon thumbnail supposed to have value
like a pokemon card has value, rare vs. commons but breeding a normal cat could make a rare one. over time the older gens will be much rarer
The same way that a stamp has value, or how a trading card has value, someone is willing to buy the asset. Sometimes it is a unique feature, like a specific run, or a misprint, and other times it is utility, but as long as people are interested in purchasing the, in this case "unique" asset (each cat is basically a programmed token with it's own DNA) then it will have a value.