Prioritize those that get you the exact colored mana you need before your first main phase
Squirrels have been a staple creature type of Magic: The Gathering ever since a particularly deranged hermit created an army of furry rodents
Pack in cheap Zombies, from Cryptbreaker to Wayward Servant, pepper it with "lords" from Cemetery Reaper to Death Baron, and supplement with anthem effects from Shared Triumph to Renewed Solidarity
Legendary Creature - Angel Ruthless Technomancer When this creature enters, you may sacrifice another creature you control
And yes, you can equip another mobilize creature with it to stack the triggers
Conversely, with Chronomaton the problem was that youd invest a lot of time and mana into a creature, and then when you finally got around to trying to do something with it your opponent could just kill it and youd have nothing to show for it but Hangarback Walker is very much the opposite unless your opponent has just the right removal spell