Quickbeam, Upstart Ent, Devoted Druid, Thopter Squadron, and Maskwood Nexus

Prerequisites

• Quickbeam, Upstart Ent on the battlefield
• Devoted Druid on the battlefield
• Thopter Squadron on the battlefield
• Maskwood Nexus on the battlefield
• Devoted Druid does not have summoning sickness
• Thopter Squadron has at least two +1/+1 counters on it

Steps

1. Activate Devoted Druid's first ability by tapping it, adding
2. Activate Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it
3. Activate Devoted Druid's first ability by tapping it, adding
4. Activate Thopter Squadron's first ability by paying and removing a +1/+1 counter from it, creating a 1/1 Thopter artifact creature token
5. When the Thopter enters the battlefield as a Treefolk due to Maskwood Nexus, Quickbeam triggers, giving Devoted Druid and up to one other creature +2/+2 until end of turn
6. Activate Thopter Squadron's second ability by paying and sacrificing the Thopter, putting a +1/+1 counter on Thopter Squadron
7. Activate Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it
8. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinitely large creatures until end of turn except Devoted Druid
• Infinite sacrifice triggers