The use of numerical ‘names’ (1,2,3 etc) is so that the name and badging of the vehicle remains constant across all markets. It is also very unusual for numeric names to cause offence in different languages.
As for animal names, well for example they are alleged to invoke thoughts of freedom in the high seas (dolphin) as well as being a likeable creature.
Funky Cat being thought of as mischievous yet likeable.
etc etc.