Yeah, I'm pretty sure that's how it worked in BG2, if I remember correctly. You got one of 9 familiars when you summoned it, based on your alignment. You had it for the whole game unless it died, and then you could summon another one, I believe. You could talk to it and ask it things or tell it to do things. You could bully it if you were an evil character. The only drawback was that if it died, you'd permanently lose 1 point of Constitution.
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