Mobs spawned from renamed spawn eggs, from using the anvil, have the name of their spawn egg, and their names appear in the death message of them killing a player. Mobs that are spawned from renamed spawn eggs, from using the anvil, can now display their custom name as nametag using an NBT tag.

What blocks can Minecraft mobs not spawn on?

Most mobs never spawn on transparent blocks, in water (except fish, dolphins, turtles, and other aquatic creatures), in lava (except for striders), on bedrock, or on blocks less than a full block tall (such as slabs placed on the bottom half).

What blocks do mobs spawn on?

Mobs can only spawn on opaque blocks, ruling out the use of glass platforms.