I Solemnly Swear I Am Up to No Good – A Harry Potter Best Seller

The phrase that opens the Marauder's Map. This fan-favorite Harry Potter tee comes in sizes from toddler to adult 3XL, perfect for theme park trips and everyday mischief. Soft and comfortable, with a print that won't crack.

Why you'll love it

• Iconic quote: one of the most beloved lines in the series.
• Toddler to adult sizes: great for family matching.
• A print that lasts: the DTF graphic is flexible and resists cracking.

Who it's for

Harry Potter fans of all ages. For groups, see our We Solemnly Swear tee or sweatshirt.

Details

• Print: DTF (direct-to-film) transfer – sharp, vibrant, flexible, resists cracking
• Garment: Rabbit Skins 3321 toddler tee, Gildan Softstyle 64000B youth and 64000 adult tees
• Fit & sizes: unisex, true to size for most; 2T–5T, Youth XS–XL, Adult S–3XL
• Colors: Black, Gray, White
• Care: wash cold, inside out; tumble dry low or hang dry
• Best for: theme park trips, movie nights, everyday wear

Mischief managed.

Processing time is 2–4 days. Delivery depends on the shipping option chosen at checkout: First Class Mail 5–7 days, Priority Mail 2–4 days, Priority Express 1–2 days. We ship only to the US.