This is a Twilight Sparkle butt. I've started with the easiest part of it, pattern as follows;
Ch 4 and connect to form a loop. 10 hdc in centre of loop.
Ch 2, 2 hdc in each st to end of rnd (20 sts)
Ch 2, 2 hdc in every 2nd st to end of rnd
Ch 2, 2 hdc in every 4th st to end of rnd
Ch 2, 1 hdc in every st to end of rnd. Repeat 12 times. (36 sts)
More will come later, but this is all I have so far. Apologies for any errata, and please have a go if you want to try it!