why c'était , because the dog is not a human being?

Question

I just wondered if we have to use C'était un bâtarde rather then il était because Pip was not a human being

Accepted Answer

Chiara, 
No, it has nothing to do with dog or human. 
The grammar here is that ‘ il/elle est… ‘ are almost never ( uncommon exceptions ) followed by a determiner-noun structure. C’est is (almost) always used when the following is determiner-noun - “ un batard “ in this example. 
See the links below for further discussion. 
 https://progress.lawlessfrench.com/revision/grammar/c-est-vs-il-elle-est-saying-it-is-she-is-he-is 
https://www.lawlessfrench.com/grammar/cest-vs-il-est/

Answer

As a good rule: when the verb is être, use ce.Tu connais cet homme? -- Oui, c'est mon oncle. -- Do you know that man? -- Yes, he is my uncle.