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Use this program only if you trashed any of your installed cards this turn.

Interface → [$1]: Break up to 2 sentry subroutines.

[$2]: +3 strength.

This card doesn't need you to sacrifice something every single turn to be used (if necessary), but it does want you to Always-Be-Sac'ing (for efficiency).

Synergies

Feeding the Fire Snake: Boi-tatá’s “Sacrifice-matters” mechanic (e.g. If you trashed any of your installed cards this turn, …) obviously synergizes with the self-sacrifice ‘trashcan’ (e.g. Gachapon’s [TRASH]: …), as well as with sacrificial additional/alternative costs (e.g. Isolation’s As an additional cost to play this event, trash 1 installed resource.).

For example, by pre-installing Gachapon or Arruaceiras Crew, if you facecheck an strong/tall sentry, you can crack them to halve Boi-tatá’s boost/break costs.

For another example, Aesop's Pawnshop can both cheapen the abilities each turn (with its clickless sacrifice) and fund either cheapened ability being used once (with the three extra credits).

Cards (self-sacrificing):

• Gachapon, Stoneship Chart Room, No Free Lunch, etc.
• Arruaceiras Crew, Boomerang, Flip Switch, etc (which also help you run more easily/safely with just a killer, by breaking/shrinking/killing/dodging non-sentries).
• Simulchip, Self-modifying Code, etc (and these can be sac'd mid-run).
• Hannah "Wheels" Pilintra, Light the Fire!.
• Daily Casts, Liberated Account, etc. (but these take time).
• Earthrise Hotel, Dr. Nuka Vrolyck, etc.
• Fermenter, Friend of a Friend, etc. (but these also takes a click without starting a run.)

Cards (sacrificers):

• Aesop's Pawnshop.
• Isolation, Spec Work, etc.

Notes

Rules:

• Because it reads any of your installed cards, it will work off resources as well as off programs/hardware.
• Because it reads you trashed, it won't work off the Corp’s destroyers (e.g. their Hagen’s ↳ Trash 1 installed program that is not a decoder, fracter, or killer.), nor off “self-exiling” hardware (e.g. Devil Charm’s and Hippo’s …, you may remove this hardware from the game. If you do, …).
• IIUC, if your “hard-purgeable” virus (e.g. Clot or eXer) gets purged (e.g. by Mavirus mavirus), still "the Runner trashed it", even though "the Corp caused it to be trashed"?

Related (other “sacrifice-matters” cards):

• Simulchip: … Ignore this cost if an installed program has already been trashed this turn.

Flavor

Boi-tatá is a fantastic creature belonging to the Guaraní mythology, it is a myth from Brazil, Paraguay, Uruguay and Argentina, this creature is a huge fire serpent that appears and attacks against those who harm the forests and animals of the Amazon. He is the Brazilian equivalent of the will-o'-the-wisp.

Its name comes from the union of two Guaraní words mbói (snake) and tatá (fire), the result being Mbói tatá in the original language (Guaraní) which means "Serpent of Fire".

Links:

• See x:"TRASH:"|"TRASH," f:Anarch|neutral-runner z:standard b:active
• /wiki/Boitat%C3%A1

In Startup right now there aren’t a lot of options for Anarchs when it comes to in-faction Icebreakers. It is this or Mimic. As Mimic has difficulty dealing with strong Sentries, it is nice to have this card as an option for Anarchs to run for no influence cost alongside Mimic in case the corp puts out something scary like Cloud Eater.

On efficiency, Boi-tatá pales in comparison to Mimic on most of the Sentries with 0-3 strength even if the Runner has trashed a card. The only weak Sentries it handles at a better rate are Tithe and Rototurret - and even then only if the Runner has trashed a card.

When looking at Strength 4 Sentries (Ansel 1.0, Ballista and Hammer), Boi-tatá runs into the awkward issue of those ice having either 1 or 3 subroutines. It is therefore particularly bad at fully breaking them when unsupported by a trashed card (5 for Ballista, 7 for Ansel or Hammer), though after a trash it becomes a much more palatable 3 or 4. However Mimic supported by Leech or Ice Carver can do the same job for 1 or 3 credits.

Then there are the big boys - Archer, Cloud Eater and Seraph. These three are tricky even for a supported Mimic to break. Boi-tatá without a trashed card breaks these for 10 which is awful but at least possible. With a trashed card though, it can break them for 6 which is a pretty excellent rate (Carmen - queen of Killers in Startup - needs 8 for Archer and 7 for the other two).

So for Startup a single Boi-tatá as an accompaniment to Mimic could be worth a look just as insurance against the big Sentries. It helps that the strength-lowering effects that are strong with Mimic deck are also quite good for Boi-tatá since they can help it overcome its biggest weakness in how inefficient it is to pump it against Sentries 1-2 above its strength.