If youre talking instances pve then the second pet is typically jungle stalker to help with might or gazelle for breakbar.
If open world main pet becomes a different conversation because stuff like jungle stalker and jacaranda are typically more useful when playing solo than tiger. A good 2nd pet would be gazelle or polar bear for the breakbar/tank combo (gazelle better break, bear better tank). Of the two gazelle is more useful more often but polar bear is a sleeper pick after the buffs, especially for those who dont yet have gazelle. Thing never dies and melts bars with its F2 lol