I also agree, it should be „beloved” instead of loved or at least be accepted as a valid answer.
There is no verb in the Russian original sentence, but the dash. Why not to translate it: Tom - my beloved tomcat ?? Without the dash (Том это мой любиьмый кот) I would agree with the suggested translation.
Russian usually omits the verb 'to be' in Present tense, English very rarely does. It makes little sense to translate a normal and natural Russian sentence with a not very natural English sentence.
Russian punctuation rules requires a dash here, regardless of whether you use «это».
I think it's important to make the distinction early to someone learning Russian fresh with DL. Also, the sentence in Russian is a complete sentence whereas Tom, my favorite cat (which was my sentence and I also omitted to be in Eng) is not a complete sentence. It could qualify as the subject of sentence followed by an appositive or qualifying statement.
If Tim is my favorite dog, and Tom is my favorite cat, does that mean I (Heaven forbid) do not have a favorite person?
It doesn't seem to me that it matters for this question: if the pets are persons, you have specified your favourite person of a particular species, who may be different from your favourite person overall; if not, then your favourite dog and cat have nothing to do with your favourite person. You can still say [Наташа] - мой любимий человек.
Кот is the masculine, кошка is feminine.
Suffix -к- is indeed often used for creating diminutive forms, but sometimes it's used for feminine forms with no diminutive meaning (like in кошка).
Diminutives would be ко́тик and ко́шечка.
The usual word for 'kitten' is котёнок.
As for ки́ска, while it used to refer to cats, I wouldn't use it in modern Russian. It underwent a meaning change, like the English word '❤❤❤❤❤', so nowadays it's not often used to talk about cats, except in double entendres.
Oh, I did not know that second meaning...awkward. Well, mother kalls me киска sometimes. Anyway, thank you for responding. Спасибо большое за ответ.
Also, I just looked it up in the Wiktionary and, apparently, it means ‘dog’ in Erzya. How ironic.
Luke and Lucy are our two cats. I wanted to rename Luke as Ricky when we got Lucy, but my wife wouldn't let me.
This may be a silly question, but why can't it be "Том – моя любимая кошка"?
Duolingo has also showed me 'Тим - моя любимая собака' - the general word for dog happens to be feminine, even if Tim is male. I thought that кошка was the general term too. So maybe Tom is only your favourite tomcat?