I recently noticed that one of my mission pets, Smoothie has an insane amount of damage mitigation and avoidance chance.
Both of her damage mitigation hits the cap of 60% and she can avoid about half of the attacks thrown at her.

Which is insane to me.

Considering that she is not a max stat. She has a bit higher stats than my main battle pet Nightshade, but currently lower level with lower level gear. Smoothie has all three prof points in agility, but Nightshade also has three in agility and also one in intell, which should mean her magical mitigation is at least higher than Smoothie's? I think that's how it works?

I even looked at a max stat pet who is attuned to shadow with three prof points in agility (thank you Jaxy) and his mitigation and avoidance chance is basically on par with Nightshade.

I sort of recently returned so I'm not exactly sure of Smoothie's origins? She might be like a prize pet or one of the festival pets where you make one yourself, I don't remember :P

Anyone know why this is happening?

I'm pretty sure the answer is that Smoothie is currently at level 60, which was the level cap before the Lost Grove was implemented. You might see those numbers change when she hits level 61? (I'm just taking a guess of course~)

no clue why its happening, but it happened with one of my mission pets, Shade. i messed around with his proficiency points (originally he had 1 int 2 agi if i remember right) and then i switched him over to 3 agi.

it might just be the way proficiency points work before level 61, but i'm not sure either. its very different on a non-max pet with the same gear too, she has 3 agi and 3 int.

I'm pretty sure the yellow numbers are "Pet vs enemy of the same level" percentages, though I don't know the calculation stats it uses. So low level pets have higher ones since equal-level enemy stats are lower, higher level, higher enemy stats, lower percentages

It's the same for all low-level pets
Here's some comparisons from our nytes that show the change in the numbers (though equips are also playing in, as well as that they don't all have identical base stats, but you can see the trend):
Lv0 (supermax)
lv25 (supermax)
lv30 (supermax)
lv50 (max)
lv59 (supermax)
lv70 (max)
lv75 (max)

(a fully primordial-equipped lv75 can get some pretty respectable numbers though, those thigns got Big numbers)