Bag of tricks + familiar = summoner?

[borg286]

So the familiar can't attack himself, but a raven/owl/ferret could feasibly pull out fluffy animals from a bag of Tricks. These items are uncommon, and while not strictly purchasable, could easily be considered cheap enough to quest for the formula and make a handful of them faster than you could a rare item. The RAW don't let you pick which animal pops out. Nevertheless the tan bag has some beefy animals inside and you get 3/day on each bag. Having a familiar use its action each round to add another beast to the playing field seems very OP considering how restricted other summon spells are.
Thankfully this is limited to a range of levels where this is useful (after you get access to the bag of tricks and before the animals become fodder). But seeing that other summon spells are concentration but a familiar with a bag is not makes this stack with buffs/BC spells cast by the caster.
Also consider that you can get Magic Initiate to get the familiar regardless of your build to add pets to the battle. This probably adds more DPR than your feat did.

While you may say, "Magic items are not for sale!!!" The same DMG does outline ways for characters to create their own magic items if they find a formula. It doesn't seem that rare+ items are conducive to crafting, but uncommon items only take 20 days to make. Well within the purview of campaign downtime.

[Vogonjeltz]

So the familiar can't attack himself, but a raven/owl/ferret could feasibly pull out fluffy animals from a bag of Tricks.

Setting aside the question of acquisition of such an item, don't the creatures pulled obey the pullee? This would call into question the ability to even direct them.

Does the item require attunement? Also problematic. What does it weigh? Is the familiar capable of carrying it let alone manipulating it?

Requires more research.

[borg286]

Setting aside the question of acquisition of such an item, don't the creatures pulled obey the pullee? This would call into question the ability to even direct them.

Does the item require attunement? Also problematic. What does it weigh? Is the familiar capable of carrying it let alone manipulating it?

Requires more research.

1/2 pound, easy for their strength (carrying capacity = 15 * str score)
Does not require attunement.
This is an uncommon item. Acquisition is only capped by convincing your DM that you can get the formula and enough of the materials. That is probably where he is going to cap you. There may not be enough star fuzz to make more than 2 bags of fuzzy toys.