Wort here can serve as a signal for spell-slinging in Red and Green,
and lets you use Goblins to copy your red spells. It's not
strictly speaking a tribal card, but you can tutor it up with
Goblin Matron and that ability synergizes really well with spells that make Goblin tokens.
Also, funnily enough, I think there are a few Cat tribal pieces that are entirely fine on their own:
I'm kinda annoyed that Feline Sovereign has that trinket text ("Protection from Dogs"), but otherwise it's a pretty solid lord.