Learn Spanish (Latin America): Este títere es muy pesado para un juguete diminuto. - This puppet is very heavy for a tiny toy.

In this sentence, para is used to set a standard of expectation or comparison. You are comparing the puppet's weight against what is normal or expected for the category of "a tiny toy." Por is used for things like cause, exchange, or duration, but never for this kind of "for a [category]" comparison.

Why do we use es instead of está with muy pesado?

We use es (from ser) because the weight is being described as an inherent, defining characteristic of this specific puppet, likely due to what it's made of. If you used está (from estar), it would imply a temporary state (like if it were soaked in water) or highlight your subjective reaction or surprise upon picking it up (¡qué pesado está!).

Besides physical weight, can pesado mean anything else?

Yes! While it means physically "heavy" here, pesado is very frequently used in Latin America to describe someone or something annoying, tedious, or overbearing. If you say a person is muy pesado, it means they are being a pain or very irritating to deal with.

Is there a difference between un títere and una marioneta?