Cho'gath, personally, has the best concept idea to this day.
He is this giant monster that just wants to constantly feast and doesn't stop until he is full. That's how he should be portrayed when playing him, Godzilla level if you would, but the other reason why I love his concept is this.
He is a giant monster that wants to eat everything but he's very intelligent and cunning.
That just sends shiver down my mind, imagine a monster that is self aware, able to use the surrounding to its advantage, knowing what your trying to pull of, or worse yet he just plays with you and lets you have a sense of calm before he devours you whole.
As for his Q ability I feel they either need to make a new animation entirely or make a new spell, the second one to me makes more sense. Its obvious that Cho'gath's kit is pretty outdated, same with his model, and will probably get a VU and a kit change. The only way I can see them keeping the Q within logic, is to make it either be:
- Tentacles, or he digs his claw's into the ground, implying that Cho'gath has spikes in his claws and they rise up to knock/pierce you.
2)He summons a rift to the Void, because hes clever not just some mindless beast, and use this kind of power to summon spikes underneath you.
It all depends on the designer at this point, what does he/she feel is Cho'gath's concept.
Personally he should feel like a monster out to kill you anything that gets in his way but clever and sophisticated with self awareness, the perfect killing machine.