Minecraft wiki entry for End_Portal_(block), associated text: End Portal blocks can be destroyed in Creative Mode. This does not affect adjacent End Portal blocks.
End portals do not reduce fall damage.‌[Java Edition only]
The top surface of an End portal is 3⁄4 the height of a full block.[verify]
The End portal is one of the only blocks without a conventional texture or entity texture; it instead duplicates and layers a starfield pattern.
If TNT is detonated on an end portal, no blocks in its blast radius are destroyed.
Ridden entities (and their riders) pass through the portal without being teleported.
The ender dragon cannot teleport through portals.
In Java Edition, the wither cannot teleport through portals, but can do so in Bedrock Edition.
If /setblock is used to place an End Portal block in the Overworld, Nether, or in a custom dimension, then the End Portal block teleports the player to the End dimension. If the End Portal block is placed in the End, then the End Portal block teleports the player to their spawn point.
Items can fall through an end portal, including falling blocks, such as TNT. The items appear in the End dimension.