Deepglow Skate's etb effect doubles all counters on any target permanents, but Juniper Order Ranger says whenever a creature enters a battlefield put a +1/+1 counter on that creature and on itself. Which one triggers first? Do I get counters on Deepglow Skate or not?
If Deepglow Skate enters the battlefield under your control while you control Juniper Order Ranger, both their abilities will trigger at the same time (one won't trigger before the other), so that they will go on the stack at the same time (C.R. 603.2, 603.3). Since you control both creatures, you can choose the order the abilities go on the stack (C.R. 603.3b, 112.8) and, thus, whether the Deepglow Skate ability or the Juniper Order Ranger ability will get to resolve first (C.R. 116.4; see also this thread). If you thus order the Deepglow Skate ability before the Juniper Order Ranger ability and target Deepglow Skate and Juniper Order Ranger with the former ability, the former ability can take into account the +1/+1 counter given to each of those creatures due to the latter ability (C.R. 608.2g, 701.9e).
What triggers first Deepglow skate vs Juniper Order Ranger