As for creatures with offspring, three worth looking at are Warren Warleader, Tender Wildguide, and Thundertrap Trainer : Warren Warleader fits nicely into the white weenie aggro archetype, giving you two lots of attack triggers and a constant churn of Rabbit tokens or stat buffs
Its effect would be handy against something like Accelgor DEX, but until a card like that resurfaces its mediocre at best
If you have ways to protect Kyler, Sigardian Emissary, odds are you will be winning the game when it has a ton of counters on it
Reject the trade, ending the process
Assuming you're an all-Pirates deck, this starts at four mana to reanimate a single creature and scales up from there
But more than that, the gradual drip feed of resources just doesnt feel impactful for Commander games, where the majority of the Undercity room triggers are non-events