"This is a first for me," he said. "It will be very different to not riding on a pony but I'm very excited and I hope to do well."
The former Western Heights High School student said his best shot at victory was in the young rider of the year field with Waitangi Wi Fi - a 9-year-old, 18 hands, Holsteiner Thoroughbred cross.
"Wi Fi also goes by the name of Archie and he's a lovely dark bay gelding to ride," Croucher said.
"I think he will be my best chance. It's funny because he has some little quirks which I will have to make sure I straighten out so I don't pick up too many fault points.
"I'm going to be up against around 30 others and it's two rounds so I need to pace myself and Archie. The event, as a whole, is a long one so it's important all my horses feel calm and happy and have enough energy out there until the end."
Croucher will ride his Waitangi Surf horse - Paris, another 9-year-old Holstenier Thoroughbred cross, grey mare in the junior field while full Thoroughbred - Forest, 14, is entered in the 1.20 classes.
Up to 1400 riders and 2000 horses will compete across 14 different categories including eventing, show hunter, pinto, para-equestrian and dressage - which has a record number of entries this year.
The Bay of Plenty is expected to make up 10 per cent of the field with the premier event in the show jumping class - the Olympic Cup on Sunday afternoon, which will feature New Zealand Olympians Maurice Beatson, Katie Laurie, and Clarke Johnstone, as well as 2016 winner Helen McNaught.
Croucher recently changed coaches from Kerikeri-based Tim Featherstone and Kate Hewlett after five years, to Cambridge-based trainer Jeff McVean.
"It was such a valuable experience with Tim and Kate and I'm very grateful for it because they offer a unique way of riding and I was able to achieve things I never thought I could. But it was the right time to move on and I have big plans for the future," Croucher said.
The ambitious rider is on a gap year - using the time to compete as much as he can and he said the Hastings event would act as an important springboard for the rest of the season.
Later this month Croucher will gain valuable experience when he travels to Australia as a groom for the New Zealand show jumping team for six weeks.
Croucher said his ultimate aim was to one day compete for his country at World Cup level and he has full backing from parents Paul and Kirsty and younger sister Alice, 15.
"This is what I want to do," he said. "My whole family has had to sacrifice and give so much to this and I couldn't have done it without them. I'm making huge strides in the sport right now and I want to keep pushing forward and reach my full potential."
2017 Farmlands Horse of the Year show:
When: Tuesday through to Sunday
Where: Hastings
Field: 1400 riders/ 2000 horses / Bay of Plenty 10 per cent
Categories: 14 - Dressage, Show Jumping, Eventing, Showing, Show Hunter, NZ Sport Horse, Mounted Games, Pinto, Para-Equestrian, Pony Club, Side Saddle, Gypsy Cob, Pleasure Horse, Welsh.