Slow and heavy. Breaks into three fast shards.
Three crystals joined at the middle, never one solid body. When it breaks, the three shards fly out the way the crystals were pointing.
A cluster of three rose crystals that walks at you at 0.55x your speed, slower than a grunt and half again as tough. Kill it and it bursts into three SHARDS that scatter, turn, and chase you at 0.97x your speed: only just slower than you while you are not shooting, and faster than you while you shoot. A shard is nearly nothing, a few points of health, and it crumbles on its own after about three seconds.
You kill it on top of yourself. The cluster was never the threat, the shards are: three bodies as fast as you, born at point blank, from every splinter in the pack you just cleared.
Kill it at range. Point the right thumb at the clusters walking in, so the shards are born far enough away to crumble before they reach you.
When shards are already out, lift your thumb and keep moving for three seconds. Running, you just about hold them off. Shooting, they catch you. You only have to outlast them.
A crumbled shard pays nothing. If you want the XP, turn and sweep them while they chase in a line behind you.
Share of everything that spawns, at four points in a run. From 1:30 one of the four new enemies is featured each minute at 2.5x its usual share, in turn.
Speeds are multiples of yours while you are not shooting. Holding fire slows you to about two thirds of that. Health grows 16% a minute, compounding, with no cap.