On the topic of Pokemon... I'm sure this has been discussed already, but how would Eevee and/or it's Eeveelutions go? Eevee's been treated as basically a separate mascot now, but much of it's appeal is the ability to evolve into a variety of different forms. But then that becomes tricky, because we'd have to integrate multiple movesets just to cover the evolution aspect. And if we cheat by having Eevee swap between multiple elements, we'll have to make multiple models just for a couple moves.
Checking the PotY poll from back in 2020 (Which is admittedly a bit skewed, being five years old now and having people vote for one Pokemon per region possibly skewing the votes, but it's still the biggest official poll we've got), Umbreon and Sylveon rank very highly at 5th and 6th place respectively. The next highest Eeveelution is Eevee itself, at 20th. After that you have to dig into the regional results to see the votes, but the highest-ranked Eeveelution outside the top 30 is Espeon. Hmm...
The obvious choice would be the classic Vaporeon/Flareon/Jolteon trio, but three whole movesets might be a bit tricky, up to four if Eevee is playable. I think the simplest option, short of just Eevee on it's own, would be an Umbreon/Espeon duo. They have relatively similar body types, are connected by similar evolution requirements, debuted in the same generation, and are both fairly popular (though Umbreon is way more popular overall). Though, that's all just me rambling here. I might be off with something.