Is the boa constrictor a producer consumer or a decomposer?

Definately a consumer. Producers are plants, decomposers are things like worms, bacteria etc. If you think about the names, they're easy to remember. And if you want to know what trophic level they'll be, well, it depends on the diagram but they'll be a high trophic, most likely the top. If you haven't done trophic levels... ignore that last bit. Hope I helped!