good is what help maintaining life as a whole, so a human with a high carbon footprint is more bad than good, but a lizard or a bird plays a role in the ecosystem, and at least doesn't have a negative pollution impact, so they're not bad

trees: that's the symbol of life, of usefulness, they help to improve life in the ground and around, hold humidity, store carbon for most of them, are homes of many species, provide food, ...

dogs or any pets: not useful at all for the ecosystem, actually detrimental from their food https://en.wikipedia.org/wiki/Pet_food#Impact and other services dedicated to them and their direct negative impact on the local wild life

mosquitoes: useful because their larva feed a large ecosystem, they also feed other insects, they also pollinate