Hope you enjoyed it! Puzzle solutions will appear here in September.
Trig monster is from the book "103 Trigonometry Problems" by Titu Andreescu and Zuming Feng.
Algebra monster is from The "Art of Problem Solving Volume 2 ; And Beyond" by Richard Rusczyk and Sandor Lehoczky.
Scribble monster is from Peter Taylor's 2018 Math Quest talk on Algebra Anomalies.