If Stangg leaves the battlefield before its ability has resolved, that ability will still create a Stangg Twin token, but its delayed triggered ability that exiles the token will never have a chance to trigger. That token will remain on the battlefield.

Stangg : règles, fonctionnement et interactions (MTG)

Stangg is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

When Stangg enters, create Stangg Twin, a legendary 3/4 red and green Human Warrior creature token. Exile that token when Stangg leaves the battlefield. Sacrifice Stangg when that token leaves the battlefield.

How it works : Stangg

Original English text — Wizards of the Coast / Scryfall

#1March 16, 2018· Wizards of the Coast
If Stangg leaves the battlefield before its ability has resolved, that ability will still create a Stangg Twin token, but its delayed triggered ability that exiles the token will never have a chance to trigger. That token will remain on the battlefield.
Card named in this ruling
Stangg Twin

Popular combos

Real combos played by the community, sorted by popularity.

#1
Stangg + Nim Deathmantle + Ashnod's Altar
Infinite death triggersInfinite creature ETBInfinite creature LTBInfinite creature sacrifice triggers
1Activate Ashnod's Altar by sacrificing Stangg, adding .
2When Stangg dies, Nim Deathmantle triggers, causing you to pay to return Stangg from your graveyard to the battlefield, and attach Nim Deathmantle to it.
3When Stangg enters the battlefield, it triggers, creating a 3/4 Stangg Twin creature token.
4Activate Ashnod's Altar by sacrificing the Stangg Twin, adding .
5When the Stangg Twin token dies, Stangg triggers.
6Holding priority, repeat from step 1.

#1
Stangg + Nim Deathmantle + Ashnod's Altar
Infinite death triggersInfinite creature ETBInfinite creature LTBInfinite creature sacrifice triggers
1Activate Ashnod's Altar by sacrificing Stangg, adding .
2When Stangg dies, Nim Deathmantle triggers, causing you to pay to return Stangg from your graveyard to the battlefield, and attach Nim Deathmantle to it.
3When Stangg enters the battlefield, it triggers, creating a 3/4 Stangg Twin creature token.
4Activate Ashnod's Altar by sacrificing the Stangg Twin, adding .
5When the Stangg Twin token dies, Stangg triggers.
6Holding priority, repeat from step 1.

Interactions with other cards

These cards' text mentions Stangg.

Stangg, Echo Warrior

Whenever Stangg attacks, create Stangg Twin, a legendary 3/4 red and green Human Warrior creature token. It enters tapped and attacking. For each Aura and Equipment attached to Stangg, create a token that's a copy of it attached to Stangg Twin. Sacrifice all tokens created this way at the beginning of the next end step.