lie alongside (someone or something)
To rest or recline horizontally next to someone or something. There wasn't anywhere else for me to sleep, so I had to lie alongside my friend in the spare bed. I just lay alongside my poor old dog stroking his face as the vet put him to sleep.
lie alongside (of someone or an animal)
to lie next to someone or an animal. (Of is usually retained before pronouns.) Jimmy came in to lie alongside of his father in bed. The puppy lay alongside its mother.