What is the object In prepositional phrase lance was covered with mud from head to toe?

The object of the prepositional phrase "with mud from head to toe" is mud.

Here's how to break it down:

* Prepositional phrase: "with mud from head to toe"

* Preposition: "with"

* Object of the preposition: "mud"

* Rest of the phrase: "from head to toe" (this describes the extent of the mud).

The prepositional phrase tells us the state of Lance – he was covered in mud.