About poem (help)

A poem is a structured writing that rhymes. So I will write a short and simple one about PET like this:

If you ask me what I have for a pet.
I will tell you l have a cat called Vet.
" Vet is not a doctor " said my Dad.
But with Vet, I never feel bad or sad.

i have a pet ,
i like it very much,
it have a long tail,
Do you know who is it ?