Just hatched a Level 1 Skrelp, bred with a Horsea, I'll post my findings for level up moves and TMs as I check them.
Skrelp
Level Up Moves
1 Tackle
1 Smoke Screen
1 Water Gun
5 Feint Attack
9 Tail Whip
13 Bubble
15 Acid
19 Camouflage
23 Poison Tail
25 Water Pulse
28 Double Team
32 Toxic
35...