It would affect all stats as the dinosaur would be sick/weakened; hit points, speed, attack, armor and crit would all be affected.
It’s not intended to make an opponent so low that they are instantly killable on the next attack but to affect the strategy they may have been planning/counting on requiring an adjustment.
Just as an example say Spit does a 10% reduction and Bite does 20% reduction;
For 2 (or 3) turns the opponent would be affected as such;
Stats: Normal / Spit / Bite
Max HP: 2800 / 2520 / 2240
Speed: 118 / 107 / 95
Attk: 800 / 720 / 640
Armor: 10 / 9 / 8
Crit: 5 / 5 / 4
The Spit / Bite moves would have no delay but would have a higher cooldown of at least 2 but most likely 3.
It would also not change a player’s current hit points, only their max hit points; I.e. in the fictitious dinosaur mentioned above, if their current hit points were at 1800/2800 and they got hit with a toxic attack the max hp would go down but their current hit points would not be affected already being below the new max (1800/2520 and 1800/2240) The other side of that is if they use a heal/regenerate it cannot exceed the adjusted max HP while it’s in effect, any overhealing is lost.