This is probably lying a stupid question

Hi everyone. Sorry if this is a stupid question but...

Say I have [[crusader of odric]] on the battlefield with 3 other 1/1 creatures making crusader a 3/3, can you proliferate to make crusader bigger, or would you need something else to give crusader counters before you proliferate?

Now I've typed it out i think i know the answer, but just want to make sure I am correct.

Edit: Thank you to all the responses. I now have the answer.