OK, rank Starfleet pets please!

Grudge Bashir Spot Tardigrades

1. Porthos 2. Grudge 3. Spot

That sabertooth tiger kid Spock had

1. Kruger’s dog B. Neelix (Reg’s cat, not the cook) Also. Phlox’s bat Cinco. Picard’s Livingston

1. M'Ress

Technically, the first Tribble om TOS is Uhura's pet, and someone on has a Tribble (fixed), so they count.