Have you tried the all powerful Form of the Squirrel, it's a powerhouse in any good squirrel deck. (That's a bad attempt at a joke). But on a serious note, you could try Deranged Hermit, it automatically produces four squirrels, and basically gives you "creatures get +1+1 until end of turn", that's if you don't decide to keep it on the field by paying it's echo cost. It seems like a good curve topper and adds more pressure to the board (coming from a guy who's played against a really annoyingly fun squirrel deck his friend owns).

Thanks for the suggestion. I have thought about the hermit, but my deck really doesn't struggle with getting out large number of squirrels, so I would rather use that spot of the curve for Silklash Spider. The spider puts a stop to flyers which I found my deck struggling with and he synergizes well with Swarmyard