Turtle Egg

Sea turtle eggs (or just Turtle Eggs) are blocks that hatch into baby turtles.

Obtaining
Turtle eggs can be obtained in the inventory using tools with the Silk Touch enchantment. If broken without the enchantment, pushed by a piston, or if a gravity-affected block falls into its space, the egg will break without dropping anything. Turtle eggs will also break when standing on them; they will break one-by one until all eggs in the block are broken.

Breeding turtles
When two turtles are bred with seagrass, one of them will burrow around in the sand and lay an egg block that contains 1-4 eggs after several seconds. The egg will go through three stages before hatching, which will only happen when the egg is placed on regular sand, and then only at night. The egg cannot begin the hatching process if it is placed on red sand. The time until hatching varies (typically taking several nights), even for eggs lain on the same beach on the same day.

Usage
Turtle eggs can be placed similarly to normal solid blocks, and slowly hatch into turtles. Up to 4 turtle eggs can be placed onto 1 block.

If a player or large-enough mob, armor stand, falling block or item falls or stands on an egg for a certain amount of time, one egg will break on the block. Most undead hostile mobs will actively seek out and trample turtle eggs, breaking egg after egg on the block until all of them have been destroyed, unless  is.