Describe the bug
A fish lizard will sometimes take two items from a stack in a player's inventory, but will only drop one of the two upon being hit or killed. The second item is gone.

To Reproduce

1. Have a fish lizard steal from your inventory.
2. If it took two of the same item, hit or kill it, to see that it drops only one of the items it took.
   Note: The items this happened with are emeralds and diamonds. Unsure if other items also have this issue, as it may have happened to other items in the past without me noticing.

Expected behavior
I would have expected for the fish lizard to drop the same number of items it took.

Screenshots
None

Info (please complete the following information):

• Modpack Version: 2.77.3
• Server or Singleplayer: Singleplayer
• Version the world was created on: 2.77.2

Additional context
None

apparently reproduced on 3.1

Reproduced on 3.2.1a.

So what happens is when the lizard grabs the item out of your inventory it takes twice the amount of the item it grabs reducing it by two while it has only has one item so killing it makes it only drop the one item while deleting the other one when it takes the item out of your inventory, i also found out it only happens in survival while in creative they only steal one

I don't think it's supposed to take two... I can't do testing, maybe someone else can?

Possible cause could be desync. If this happens again on 3.0, feel free to reopen the issue.