Even if you play her for 5 mana and simply use the first active ability, it's still worthwhile as the solid planeswalker and a 6/6 creature token in a single turn are both great
The only issue here is that she casts six mana, not easy to do outside of Green, but she's in White, one of the lesser colors of ramp, so if she's answered or countered you might make her very rough to recast with Command Tax
I found this out when I wrote an article talking about the design for Bestial Menace, which I assumed had followed a similar path to Moose and Squirrel, only to learn from Kelly that he had designed the card
Creatures : Coalition Honor Guard, Standard Bearer, Trinket Mage, Shriekmaw, Bone Shredder, Man o War, Mulldrifter, Pawn of Ulamog, Clone, Windborn Muse, Entomber Exarch, Wonder Mixed in with the good, solid utility creatures are some ways to protect Ertai in the form of the Flagbearer creatures Coalition Honor Guard and Standard Bearer
Your $15 entry gets you more than just a seat at the table