https://considerveganism.com/counter/

Not even just land animals (although that's 100% true). Life-for-life, land animals would be exceeded by wild-caught fish (conservatively) in a matter of days if literally the entire world went vegan in a microsecond and literally every farmed land animal on Earth were slaughtered at the same instant. Humans arguably couldn't even practicably keep up the worldwide mass-slaughter pace just compared to wild-caught animals within this ridiculous anti-vegan fever dream.

Edit: Say there are 30 billion land animals as livestock. Assume on the very low end that 1 trillion wild fishes are caught every year. This would mean you'd be killing 1/33 of the annual wild fish catch in a microsecond and that it'd take you about 12 days to, life-for-life, exceed the instantly killed entire land livestock population from wild-caught fishes alone. As icing on the cake: "We estimate that 124 billion farmed fishes were killed for food in 2019.", so contract that down to less than 10 days if you count fish overall.