Making a token on end step is much worse than on upkeep. Given the general pattern going on here, 1/2s are really awkward and this will quickly spiral into a board stall. Instead, let's make them 2/1s with menace.
There are a few ways to go with it here, depending on the format. It feels like it spirals out quickly which means early on, it's much riskier than late, especially when non-optional. When it makes two copies per turn, menace allows two to block one, which optionally allows the attacker to choose whether to destroy one or both. The existence of this choice cares about whether the token creation is something that is automatic or not and any slight variation would need a lot of testing to get the costs/wording in place where things feel good from both sides.
1R2/1 Menace When this attacks, the defending player create a token copy of it. 2R2/1 Menace At the beginning of your upkeep, target opponent creates a token copy of it. 3R2/1 Menace At the beginning of your end step, target opponent creates a token copy of it.
Do any of these want haste so you can attack immediately? Haste feels weaselly and the tokens having it doesn't change anything. A version with an attack trigger cares a lot more about this to guarantee a body is created, but at the same time, the other player can choose to never make more copies with it. The menace matters a lot more in this case since attacking is never automatically handicapped by the token created in combat.
Depending on the ultimate outcome of the design, particularly if it's an automatic trigger that happens without the defender being able to do anything about it, I could see this needing to cost 2RR or 3RR, both due to the amount of stats the token doubling would generate and to also delay when the doubling starts so that board wipes are online.
Packaging this up for commander:
Weasel War Pack | 3RR
Creature - Weasel (R)
Haste, menace
At the beginning of your end step, target opponent creates a token copy of this.
The dance confuses their prey before the final strike. 2/1
Looking at the damage numbers is complicated. With no blocking, while you do get more damage in early, I think you ultimately lose the race if that early damage lead is not enough. You'd want something like Electrickery to or a Fog to flip a turn to your favor. This is all before you add in things like Impact Tremors, sac outlets, and general blocking. If you and another player are working together, it also plays out differently.
I was kind of looking to make a card that would stall out the board without outside help from your other cards. While I like the idea of making them more aggressive, it wasn't the intent for the card, and I don't think weasels would be menacing to other weasels, so maybe Intimidate or even Skulk would be better. First Strike could also dissuade blocking, but it would kind of render most opposing non-Weasel creatures also unable to attack into the Weasel Phalanx, which was not my intent. I think an upkeep trigger would be too slow to get the ball rolling, and an End Step trigger makes decisions more important in multiplayer (You can give the player to your left a weasel for more of them overall, or to your right one for less of them.)
It's kind of a nightmare to make this a good card and yet not broken. But what I'm looking for is something that starts off derpy and ends up scary, perhaps due to your other cards. Think Tribbles. I don't think there's a way to make this sac-outlet proof without having some dumb text on it, so I'm not going to attempt that one.
I don't totally agree that this needs to cost 4+ mana. I could be wrong. But your versions are still pretty cool!
Creature- Weasel
At the beginning of your end step, target opponent creates a token copy of Crazed Weasel Pack.
1/2
There are a few ways to go with it here, depending on the format. It feels like it spirals out quickly which means early on, it's much riskier than late, especially when non-optional. When it makes two copies per turn, menace allows two to block one, which optionally allows the attacker to choose whether to destroy one or both. The existence of this choice cares about whether the token creation is something that is automatic or not and any slight variation would need a lot of testing to get the costs/wording in place where things feel good from both sides.
1R 2/1 Menace When this attacks, the defending player create a token copy of it.
2R 2/1 Menace At the beginning of your upkeep, target opponent creates a token copy of it.
3R 2/1 Menace At the beginning of your end step, target opponent creates a token copy of it.
Do any of these want haste so you can attack immediately? Haste feels weaselly and the tokens having it doesn't change anything. A version with an attack trigger cares a lot more about this to guarantee a body is created, but at the same time, the other player can choose to never make more copies with it. The menace matters a lot more in this case since attacking is never automatically handicapped by the token created in combat.
Depending on the ultimate outcome of the design, particularly if it's an automatic trigger that happens without the defender being able to do anything about it, I could see this needing to cost 2RR or 3RR, both due to the amount of stats the token doubling would generate and to also delay when the doubling starts so that board wipes are online.
Packaging this up for commander:
Creature - Weasel (R)
Haste, menace
At the beginning of your end step, target opponent creates a token copy of this.
The dance confuses their prey before the final strike.
2/1
Looking at the damage numbers is complicated. With no blocking, while you do get more damage in early, I think you ultimately lose the race if that early damage lead is not enough. You'd want something like Electrickery to or a Fog to flip a turn to your favor. This is all before you add in things like Impact Tremors, sac outlets, and general blocking. If you and another player are working together, it also plays out differently.
Older Magic as a Board Game: Panglacial Wurm , Mill
It's kind of a nightmare to make this a good card and yet not broken. But what I'm looking for is something that starts off derpy and ends up scary, perhaps due to your other cards. Think Tribbles. I don't think there's a way to make this sac-outlet proof without having some dumb text on it, so I'm not going to attempt that one.
I don't totally agree that this needs to cost 4+ mana. I could be wrong. But your versions are still pretty cool!