Each Celestial Crustacean defeated counts +1 towards the progress bar. Not counting other factors, this will take a little over one full energy bar (~100% energy) to complete this, assuming you use a Lucky Foot on each NPC and you do not spend your energy on anything else.

Oh no! This aggressive creature is radiating with interstellar energy! You should end it before it spawns more of its kind.
Action	Result	Reward
Attack!	Initiates a fight with a Celestial Crustacean.	Acts as a regular battle, so you can gain SB, Experience, and Impression if battle is won. No residue is awarded for this fight.

Oh no! This aggressive creature is radiating with interstellar energy! You should end it before it spawns more of its kind.
Action	Result	Reward
Attack!	Initiates a fight with a Celestial Crustacean.	Acts as a regular battle, so you can gain SB, Experience, and Impression if battle is won. No residue is awarded for this fight.

Oh no! This aggressive creature is radiating with interstellar energy! You should end it before it spawns more of its kind.
Action	Result	Reward
Attack!	Initiates a fight with a Celestial Crustacean.	Acts as a regular battle, so you can gain SB, Experience, and Impression if battle is won. No residue is awarded for this fight.

Oh no! This aggressive creature is radiating with interstellar energy! You should end it before it spawns more of its kind.
Action	Result	Reward
Attack!	Initiates a fight with a Celestial Crustacean.	Acts as a regular battle, so you can gain SB, Experience, and Impression if battle is won. No residue is awarded for this fight.

You can view your progress as you explore on the Journey to Vredefort Crater page. With each successful battle against a Celestial Crustacean, your NPC count will go up.

Once they have been claimed, they can be bred, chased, killed, nature reserved, raffled, traded, or transferred off. As soon as they are off of claiming cooldown, you can do whatever you want with the lionesses - you do not need to hold onto them until you complete the quest.

The best way to finish this quickly would be to use Catnip and ensure you have 30 free territory slots open.

It does not require the player whose den page you're on to be online. You can go through all offline accounts one by one and complete this quest.

You can also use the "# member(s) online" link on the sidebar to find players that you can "Spread the Word" on, as that page displays 20 different players at one time.

The players must be unique, and you cannot "Spread the Word" on the same player more than one time.
This also counts the 250 players that you previously "Spread the Word" to.

It's a good idea for you to have the Journey to Vredefort Crater page up in another tab and periodically check it, as there is no visual indication about what number den you're on.