mate for sucker fish

Question
QUESTION: I would love to purchase a mate for my sucker fish.  It is giant and the family who had him before me said that he bullies smaller .  What would be appropriate to buy?  He is about 5-6 inches long.

Thanks!

ANSWER: There are hundreds of species of "sucker fish".

I need to know exactly what your's is before I can answer this question.

---------- FOLLOW-UP ----------

QUESTION: My sucker fish is black with light spots.  He is huge and I dont want him to EAT other fish.  Before I buy one, I would just like to investigate a little.
THanks!

Answer
Still not good enough. I can think of dozens of fish off the top of my head that could look like that. The only thing I can really tell is that it is probably a pleco.

I need a pic, a name, a scientific name, or a pic on the internet of a fish that look very very similiar to yours.

-Nick