Stahp right there!
GOOP
Goop for the Chomper is an ability exclusive to the GW series. This ability throws out a goop projectile which reduces the movement speed of enemies and their turn rate harshly, that you hit directly or you dealt splash damage to, as well as negating their abilities for a short time, although this ability does minimal damage. This makes it easier to eat an enemy from behind as they turn around really slowly and are unable to escape, or it makes it much easier for your allies to vanquish those affected enemies. This ability has a short cooldown as well, so this gives Chomper a decent ranged attack that they can use frequently for easier vanquishes. I really like the concept of this ability and the ability itself, this can prove to really benefit your team with easier vanquishes and allows the Chomper to eat them with ease as well, as long as you can get up to the enemy quickly before the Goop expires.
GW Alternate Abilities
Super Sticky Goop: This ability launches a different type of Goop that completely prevents enemies from moving when they get hit by this and it lasts slightly longer compared to regular Goop. It deals even less damage again and has a slightly longer cooldown, and enemies are still able to turn around and shoot with their primary weapons. Apart from all these changes, this variant of Goop is the same as the regular variant. This can be really useful for making enemies almost completely unable to do anything at all for easy lunch or vanquishes from your allies. I find this ability quite useful, it makes Goop even more effective and beneficial to you and your team overall, but some drawbacks which does not make this ability too overpowered.
Cheesy Goop: This ability is exclusive to GW. This ability launches a different variant of Goop that does significantly more damage than the regular Goop, but it has a higher cooldown which means missing your Goop is more costly overall. This could be useful if you wish to use Goop as more of a supportive ability, rather than offensively, as the enemies will take more damage and make it easier for your allies to finish them off while keeping the regular Goop properties, and you do not need the extra damage if you are trying to eat your enemies anyway. I have not seen this ability in use as I have not played the GW, although I think that this seems like a useful ability, as this can be used in a more supportive way to assist your allies with easier vanquishes, although you can still eat those Gooped enemies if you prefer.
Chomp Cannon: This ability is only available in GW2, and this is the only GW2 exclusive ability that is not obtained exclusively through Rux, rather Sticker Packs only. This ability instead fires an explosive Goop, which deals heavy damage to enemies that are hit directly by it with no damage dropoff and it deals some splash damage as well, although it takes a delay before this is successfully fired, has a much longer cooldown, and does not have the regular Goop properties. This is useful for giving the Chomper a viable ranged attack or to vanquish specific enemies with ease. I find this ability cool, it gives Chomper an effective mode of a suprise attack and a way to deal good range and at range unlike the Chomper's other attacks, and possibly getting some helpful instant vanquishes as well.
GRODY GOOP
Grody Goop for the Chomper is an ability that is only available in BFN. This ability throws out a toxic goop cloud which negates the abilities and sprint of enemies that step into it, and if an enemy remains in it for too long, they will take significant damage and be inflicted with a toxic effect, which will deal small but continuous damage which will last a while, and the enemies inflicted with this toxic effect can also spread it to their allies, meaning you can deal lots of damage to enemies at once and negate their regeneration, although do consider that their healers can counter this effect. I find this ability immensly useful but honestly sort of overpowered, as the damage is insane and the toxic damage can vanquish enemies that have less health without much trouble. This should be nerfed, but having a crowd control based ability like this is really cool.
BFN Alternate Upgrades
Upset Stomach (2 upgrade points): Your Grody Goop lingers for longer, which essentially means denying area for longer and possibly dealing more toxic damage for enemies, due to the incteased duration that it will last. The lingering toxic effect can even last after the Grody Goop expires so this upgrade will make this ability even more effective. I think this ability is useful, being able to deal even more damage and spread even more toxic damage, although Grody Goop is already greatly powerful.
Dirt Bath (3 upgrade points): Making contact with your Grody Goop gives you a movement speed and attack speed boost which is applied while you are in it, and this lasts for a little while after exiting it as well. This can be really useful by being able to vanquish caught enemies with ease and you can use this ability as a way to boost yourself rather than relying on making contact with enemies to get use out of this. I would say this ability is helpful, as you can use this ability as a way to buff yourself, as well as being able to deal immense damage to enemy groups.
Conclusion
These abilities are really useful in many situations and there are many alternate abilities to try out as well. It makes enemies much weaker, by being unable to use their abilities to fight back, not being able to escape and greatly slowing their movement and turn speed, making for easy vanquishes for you and your allies, or just being able to eat them much more easily due to not being able to escape. I find this ability great, because it has many uses and it can really help to support you and your team.