"That animal is eating meat."
Translation:Tamto zwierzę je mięso.
Zwierzak is a bit colloquial, and has these... affectionate connotations. We do not accept it.
Does making a noun diminutive change it's gender? Do nouns in the diminutive conjugate like the rest of them?
Diminutive rather shouldn't change the gender, although that's possible, I guess. Especially if we treat words for baby animals as diminutives. Then you will have "słoń-słoniątko", "lew-lwiątko" and similar.
A noun is still a noun, so of course it will conjugate according to how it itself looks like. It doesn't matter if it has been derived from some other noun.
The determiner has to match the gender of the noun it describes. "tamto" is used for neuter nouns, such as "zwierzę". "tamta" is used for feminine nouns, such as "kawa".
Then you have "tamci" (masculine personal plural) and "tamte" (not masculine-personal plural).