The odds of getting the pet in the example that has some of the rewards already pulled are wrong. Odds listed are 4.7985% instead of 0.1919%. In the example there is 521 weight remaining, 1 of which is the pet, making the odds of pulling it 1/521 or 0.1919%.
Can’t include link to page but it is the one that the game client links to.
It baffles me we can’t link to Blizzard support articles in the forums.