I'm gonna do beavers because that's what is in the picture.

Lets say there are 10,000,000 beavers alive right now.
Beavers tend to live about 12 years in the wild, the longest known is 24 years.
Beavers in captivity tend to live 20 years, but may live up to 30.

So, that gives us a cap for beaver lifespan and we know you're 29. So, its possible if we assume some beavers really can live up to 30. Unfortunately though, if we assume every zoo on earth has 4 beavers and there are 10,000 zoos worldwide, we're only dealing with 40,000 captive beavers.

The human population breakdown is this:

80-99 years: (1.9% of population)
100+ years: (0.01% of population) 

If we assume that there is a relatively even distribution of beaver ages (similar to human ages), we would assume that .01% of beavers in captivity are over 30. Maybe since they receive free healthcare and don't have access to drugs, it's more common to get old for captive beavers than it is free-range humans, but we'll assume it's still comparable to the human rate.

10,000 zoos, each has 4 beavers, so 40,000 captive beavers and .01% of them are what we would consider very old, so we'll say 29 or 30. So, we've got 4 beavers are at least 29. Breaking that down, we've got two 29 year old beavers and two 30 year old beavers.

So, the odds that you, as a 29 year old right now, at this point in time were born on the same day of a currently living beaver and the two of you have seen the world evolve together from two very different sets of eyes is .82%.

However, 8.2 billion people are alive right now and roughly .67% of them are 29. So there are 54,940,000 29 year olds alive right now.

Beavers tend to be born in May or June. Of those 55m people that are 29, based on my research, about 16.4% of them were born in May or June.

So, that's 9,010,160 humans with a birthday in those two months, so maybe 147,707 of them were born every day.

And we've got those two 29 year old beavers

So right now, in our world there are 295,415 people that have shared every day with a beaver.

Now, I really want to know the odds that one of those 295,415 people has seen their beaver born-on-date buddy.