All I can remember is that its about a boy and he has an imaginary friend. Except the friend isn't imaginary it is some invisible creature. I remember a scene when the kid is trying to make the creature some sort of green drink it needs and he messes up the kitchen and gets in trouble.

It's possibly Fuzz Bucket.

That's it! I found the scene on YouTube and everything. Thanks.

"Last name?"

"Gerber"

"Gerber like the baby food? Ahahahahahaha..."

I totally forgot about fuzz bucket I used to love it as a kid