>>35693788For me, it really depends on the object. I'm fine with Litwick, and Grimer, but not as big on Vannillite, or Trubbish, for example.
For me, Litwick works because it has weird ghostly fire, already making it more than a normal candle, but the fact that it's a ghost makes it more passable in how it would function. Similarly, Grimer is nice because it's an amorphous blob monster. It isn't a specific kind of pollution, and it looks very fluid with its markings and how it would ooze around.
Trubbish and Garbodour, for comparison, look odd with their general brown color with bright spots to stand in for trash. I know they couldn't sprite in a pile of real trash, but that just makes it seem half-hearted. Being bound up in a green garbage bag just makes it feel a bit lazy. It doesn't feel like they wanted to make a cool living garbage monster, just like they wanted to make a pokemon based on trash and did so out of obligation.
Vannilite gets more hate than it deserves, but it's still very odd. The fact that they float adds strangeness to them, and the fact that they're supposed to be living icicles, but also have strange elements like growing an extra head and a straw so it resembles a sundae even more hurts it. Again, it feels like somebody really wanted an icecream pokemon to be made, and they just went with the first design they had.